the /load_uisettings loads nothing more than window positions and chat channels. A matter of fact if you don't leave the current channels before using that you'll find a few repeats of the same channels you join using the command.
The quick raid buttons are loaded looked at when the game loads and the UI is initialized. The code for defiler is
<Page Name="Defiler">
<Data Name="Button1" Macro="SpellForMyLevel='Ancient Shroud VII'
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 78)
SpellForMyLevel=COND ? 'Ancient Shroud VI' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 68)
SpellForMyLevel=COND ? 'Ancient Shroud V' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 54)
SpellForMyLevel=COND ? 'Ancient Shroud IV' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 40)
SpellForMyLevel=COND ? 'Ancient Shroud III' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 26)
SpellForMyLevel=COND ? 'Ancient Shroud II' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 19)
SpellForMyLevel=COND ? 'Ancient Shroud' : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(12) Ancient Shroud
(19) Ancient Shroud II
(26) Ancient Shroud III
(40) Ancient Shroud IV
(54) Ancient Shroud V
(68) Ancient Shroud VI
(78) Ancient Shroud VII"/>
<Data Name="Button2" Macro="SpellForMyLevel='Dire Balm VIII'
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 71)
SpellForMyLevel=COND ? 'Dire Balm VII' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 57)
SpellForMyLevel=COND ? 'Dire Balm VI' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 43)
SpellForMyLevel=COND ? 'Dire Balm V' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 29)
SpellForMyLevel=COND ? 'Dire Balm IV' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 22)
SpellForMyLevel=COND ? 'Dire Balm III' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 15)
SpellForMyLevel=COND ? 'Dire Balm II' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 7)
SpellForMyLevel=COND ? 'Dire Balm' : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(1) Dire Balm
(7) Dire Balm II
(15) Dire Balm III
(22) Dire Balm IV
(29) Dire Balm V
(43) Dire Balm VI
(57) Dire Balm VII
(71) Dire Balm VIII"/>
<Data Name="Button3" Macro="SpellForMyLevel='Sacrificial Restoration VII'
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 73)
SpellForMyLevel=COND ? 'Sacrificial Restoration VI' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 60)
SpellForMyLevel=COND ? 'Sacrificial Restoration V' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 46)
SpellForMyLevel=COND ? 'Sacrificial Restoration IV' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 32)
SpellForMyLevel=COND ? 'Sacrificial Restoration III' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 18)
SpellForMyLevel=COND ? 'Sacrificial Restoration II' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 10)
SpellForMyLevel=COND ? 'Sacrificial Restoration' : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(3) Sacrificial Restoration
(10) Sacrificial Restoration II
(18) Sacrificial Restoration III
(32) Sacrificial Restoration IV
(46) Sacrificial Restoration V
(60) Sacrificial Restoration VI
(73) Sacrificial Restoration VII"/>
<Data Name="Button4" Macro="SpellForMyLevel='Deathward'
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 80)
SpellForMyLevel=COND ? 'Soul Ward' : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(80) Deathward (80)
(AA) Soul Ward"/>
<Data Name="Button5" Macro="SpellForMyLevel='Vivication'
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(50) Vivication"/>
</Page>
and for fury is
<Page Name="Fury">
<Data Name="Button1" Macro="SpellForMyLevel='Regrowth VII'
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 78)
SpellForMyLevel=COND ? 'Regrowth VI' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 68)
SpellForMyLevel=COND ? 'Regrowth V' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 54)
SpellForMyLevel=COND ? 'Regrowth IV' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 40)
SpellForMyLevel=COND ? 'Regrowth III' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 26)
SpellForMyLevel=COND ? 'Regrowth II' : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 19)
SpellForMyLevel=COND ? 'Regrowth' : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(12) Regrowth
(19) Regrowth II
(26) Regrowth III
(40) Regrowth IV
(54) Regrowth V
(68) Regrowth VI
(78) Regrowth VII"/>
<Data Name="Button2" Macro="SpellForMyLevel="Nature's Elixir VII"
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 73)
SpellForMyLevel=COND ? "Nature's Elixir VI" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 60)
SpellForMyLevel=COND ? "Nature's Elixir V" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 46)
SpellForMyLevel=COND ? "Nature's Elixir IV" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 32)
SpellForMyLevel=COND ? "Nature's Elixir III" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 18)
SpellForMyLevel=COND ? "Nature's Elixir II" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 10)
SpellForMyLevel=COND ? "Nature's Elixir" : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(3) Nature's Elixir
(10) Nature's Elixir II
(18) Nature's Elixir III
(32) Nature's Elixir IV
(46) Nature's Elixir V
(60) Nature's Elixir VI
(73) Nature's Elixir VII"/>
<Data Name="Button3" Macro="SpellForMyLevel='Back into the Fray II'
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 72)
SpellForMyLevel=COND ? 'Back into the Fray' : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(52) Back into the Fray
(72) Back into the Fray II"/>
<Data Name="Button4" Macro="SpellForMyLevel="Nature's Salve VIII"
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 71)
SpellForMyLevel=COND ? "Nature's Salve VII" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 57)
SpellForMyLevel=COND ? "Nature's Salve VI" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 43)
SpellForMyLevel=COND ? "Nature's Salve V" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 29)
SpellForMyLevel=COND ? "Nature's Salve IV" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 22)
SpellForMyLevel=COND ? "Nature's Salve III" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 15)
SpellForMyLevel=COND ? "Nature's Salve II" : SpellForMyLevel
COND=(Parent.Parent.Parent.Parent.Custom.ProfitUI_QuickRaidButtons.ActualLevel.T ext < 7)
SpellForMyLevel=COND ? "Nature's Salve" : SpellForMyLevel
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(1) Nature's Salve
(7) Nature's Salve II
(15) Nature's Salve III
(22) Nature's Salve IV
(29) Nature's Salve V
(43) Nature's Salve VI
(57) Nature's Salve VII
(71) Nature's Salve VIII"/>
<Data Name="Button5" Macro="SpellForMyLevel='Primeval Awakening'
useabilityonplayer Parent.Target SpellForMyLevel" Tooltip="(50) Primeval Awakening"/>
</Page>
and the proper code is I believe loaded via the subclass detection routine. If that file became bad or out dated it would fail to work all the way around it wouldn't select defiler while on fury or vice versa.