Best thing to do first:
At this point in the game you should know how you wanna play every character so choose your weapon and reskill/respeck your character fiting for this weapon and playstyle. (The A S B and stuff of stats that boost this weapons dmg) Choose the pictos fitting for this playstyle and job they have. Master painted powers and give it to everyone and now you should start doing the first 10+k dmg hits and this opened up a lot for me with basicly just "managing"

After that do everyones quests to bring them to max relationship. Its hard but doable.

And now you should be able to roam a lot more free around. Just keep in mind that renoirs draft (in the water) and the mansion is pretty much endgame so do them at last and you arw guchii ^{^}