pdb1: It would make sense that they feed and need each other for your golfing experience to run properly.
Not so. Advice for years has always been to close the main page if you start the game by hitting Play Now. There is zero reason to have the main page open while playing the game. I start the game from a bookmark that goes around the main page.
pdb1: The auto ball replacement ,purchase prompt. If your " other screen isn't running you wont be able replace or reequip your balls during play
Yes you can. Balls can definitely be purchased during a round and if you buy the ones you started the game with, they immediately go into your bag to use, regardless of whether or not the main page is open. It doesn't even open to get the balls you bought during the round.