There is nothing you can say to convince me that's a good idea. Nothing. I've also never heard of a deception cleric, and I suspect neither has the average gamer who has never played AD&D. Roll on the mods that fix this BS.
It's a nice alternative if you don't want a thief in the party. She can open locks, disable traps, is good with a shortbow, and gets a level 2 spell called "pass without a trace", which greatly helps with sneaking for the entire party. Regarding spells & hotbars, my recommendation would be to turn off everything except spells in the options. That way the hotbar won't get cluttered whenever you pick up an item. I keep the add/remove spells option, because then spells get automatically swapped whenever rearranging spellbooks, which I tend to do quite often.
If you are looking for an alternative way out of the citadel, there is one more exit through the rooms of priestess Gut (I'd suggest sneaking through there, because she has a tough bodyguard). To get there, easiest is by sneaking on the rafters; just strip your party of any armor that grants a disadvantage on stealth (should be in item description). Shadowheart can help with her "pass without a trace" here. If she has any level 2 spell slots left, she can change what is memorized, as long as it is outside of combat.
Once you climb the rafters, you can also easily "stealth kill" the goblins in the main hall: shoot and hide, and enemies will waste their turn. I think it's left shift that you press in combat to highlight enemy vision cones. If you attempt to hide outside of the vision cone, your character will succeed. Keep in mind that "shoot & hide" trivializes a lot of encounters in BG3, because enemy ai currently cannot handle stealth detection. If your character is too far away, they won't even attempt to search during their turn in combat.
