You have a fair deal of both silvers and gold. If you want to CR/SU some of the golds then that should be perfectly fine, just CC a silver to replace it as AW fodder and you're good to go.
As for rainbows, i'd use them either on Maribel or Sophie. Both of them rely quite heavily on their skill being up. Also consider what units you want to skill awaken later when we get that. Not all skill awakenings are super impressive, so just check Lafate's sticky thread.
Map-wise i have no idea. Personally i just farm immortal beast when i have nothing better to do like event maps.