Thank you for your input.
From the shops you rank, Academy is part of the Truth group and they do not allow foreigners in any of their shops.
I'm also doubtful about Louvre since they are sister shop to Yuzuki and Yuzuki do not allow foreigners.
Platinum Stage weren't really jumping for joy the two times I visited, I only got in because of a last minute cancelled session, and the second time they just told me to try Putit Royale instead. As such I can't really recommend them for foreigners because of this attitude.
Aqua Palace not confirmed for foreigners either, and I sort of get the feeling they should be by now if they allowed gaijin.
Since you list so many shops that according to my info do not accept foreigners, I would assume you are either Japanese or you are Asian and fooled them into thinking you were Japanese.
I'd say getting a girl's LINE is great if it means you can book her directly at the shop without involving the shop staff. I have this setup with my JAV star fave and it's amazing.
Asking for dates outside is a bad idea though, not only is it against the rules of the shops, I don't really think most girls would be interested unless you are a long time regular and she's really into you, but being seen with a foreigner should probably put most girls off this idea. If she would be seen with you basically her "career" would be over as the message board stalkers would slut shame her and force her to quit most probably.