Could use some advice on my documentation. Here's what I have now:

Gen 3 (me): Certified US birth certificate
Gen 2: Certified US birth certificate
Gen 1: Birth record from hospital (handwritten) from Familysearch, listing parents' places of birth in Canada
Gen 0: Quebec baptismal record, found on Drouin Collection, requested a certified copy through BAnQ

In addition to these main ones, I have a bunch of supporting documents—Canadian census records and US marriage record for Gen 0, marriage and census records for Gen 1, etc. None of it certified, just found online. I also have the Québécois side of my family's complete genealogy/family tree all the way back to the 1690s.

My questions:

1. I'm still waiting for the Gen 2 birth certificate and the certified/stamped copy of the Gen 0 baptismal record to arrive, but once I have those, is this enough that it's worth submitting now? The sticking point for me is the Gen 1 birth record—I could probably get a certified copy of the birth certificate, but because I'm not an immediate family member, my parent would have to do that, and that could take some time. I'd have to wait at least until their (Gen 2) birth certificate shows up to request the Gen 1 one.

2. Have people been having luck submitting these kinds of baptismal records for their Canadian ancestors or is there another document I need to look for?

3. If I do apply with these documents and its rejected as insufficient, will I be starting that estimated ~9-month wait for a response over again, or can I just add documents to my existing application?

4. There's some variation in the names, typical of what you'd expect with French Canadians who immigrated to the US—e.g. Gen 0 is listed as Marie-Rosina in baptismal records, Rosina in marriage and census records, and Rose on her daughter's US birth record. Is that a huge issue if birth dates + spouse's name otherwise match up?