Alice(sp rec to def) Felice(sp spark bc) Ark Fina Zeruiah Friend with B.B. Buff(ex. Azurai) Is this a good squad? What sp options should I go for zeruiah?
Squad is not functional. Does not contain a mitigator (50% dmg reduction buff on BB/SBB). Squad appears built with defenses in mind (e.g. Alice rec to def, Fina in squad), so it's clearly intended as a general hard content clear build, but it doesn't contain the most important survival buff. Zeruiah has elemental mitigation and Azurai/Ark have LS mit, but you still need a proper mitigator for that full 50% value. A Fina squad should have pretty good uptime on UBBs and good UBB mit options, but again this doesn't replace the need for a mitigator. If you have Omni Ark, it clearly means you have a mitigator and understand what it's for, so... presumably you should be able to include one in the build.
There's pros and cons. Hisui gets you a vastly better rec->def stat convert in that slot. Juno-Seto can be SP'd for it but her value's lower than, say, Hisui or Alice. But if you use Juno you do get the benefit of HoT (which is currently missing from your build and does matter in some places, to deal with DoT), and you get the rez on Juno. Hisui carries block enhancement but in most situations that isn't useful.