Would definitely get a BAP. The amount of fuel flow needed to run nitrous and E85 I imagine would required it. As far as the injectors I'm not 100% sure on those. If they do work I believe they would be at their limit
It's really just the pump I would need to worry about. Not the injectors I'm thinking. The pump is supplying the fuel to make that mixture right on the kit. I'll start small and tune from there
That sounds like a good start. I would just pick your poison ( nitrous or e85) and fully tune just one of those and see where your at as far as fuel goes. My opinion is fully tune for e85 first, check how the injectors and pump are doing, then start small increments of nitrous if possible