Unfortunately, if you go Mage build by selecting Timid personality then you won't be able to juice, so no sex damage on that front, if ennemies get a grab of you and fuck you you're mostly screwed. Mage build is purely magic damage, so mostly WIS, there's many advantages to going with Mage build, especially in late game.
Higher WIS means higher selling price of items, higher chance of avoiding dangerous encounter through talk and sometimes observe, special choice option unlocked during some quests. Mage build has access to A LOT of skills that makes it the best jack of all trade in the game, it can deal very well with stealth, close and ranged combat, and can also act like a necromancer by doing summoning (far more effective with Abomination race).
Mage build is by far the most fun class in the entire game atm, so I would advise you to go with it even in early game, though you won't be able to use magic until you unlock the "Magic knowledge" trait at level 15, but it's a level that is very easily reachable if you know the tip to gaining experience, like masturbating or doing some quests like Sea Witch quest that don't require fighting, saving the raped captives.