Hello there!
I'm glad you are enjoying the game so far, and makes me a little sad that I cannot help you to solve the problem with subaru and anya, since I have no current plants for any update of the game.
The problem with the party limit though can be fixed if you go to the beds in the office (the further to the left room), that will reset your team and should allow you to get 5 party members again.
Hope at least this can help you a little with your progress!