Nah it's reversed. She gets negative avoidance but that's it everything else is good bonuses which fits her character. Nope. Jesse and Silque have a support bonus instead of a convo if you use them in chapter 6 and 5 but that's it. Other than Alm and Celica having support boosts obviously. Also no you shouldn't. Faye makes a worser case than Atlas. At least you can save Atlas completely and utterly by making him a merc. You can't be a merc nor an archer with Faye and Celica already has an offensive healer, Alm does not. Faye even has the again spell pretty sure no other unit naturally has which is more effective on Alm's route. Faye also starts off really under-leveled compared to the rest. It's good for nothing but an easter egg but putting her and Kliff with Alm is absolutely the right choice. Celica's route is filled to the brim with mages so making her a mage in Celica's route is redundant and she will fall behind anyways due to being under-leveled. Just keep her with Alm where she actually can support with somebody (Silque, Alm) please.