Yea, sadly you still cannot change any of the keybinds for some reason, even though you can access a menu to do so. Got to AR7 last night on the PS4 and did my rolls, didn't get anything I'd like unfortunately (Noelle, Razor and Bennet). The PS4 Pro is capped at 30fps, so I think I'll play on PC.
If you're on PC, and don't mind putting in the time to "reroll" you can do so by just making usernames instead of having to make emails each time. Makes that step easy at least. Following a "speedrun" guide to hit AR7 takes about 25-30min, I'll do that a few times before I say F-it and take what I get.
There are a few Currencies to be aware of:
Primogems - These are the basic currency that you get from doing everything in the game. It takes 160 of them to do 1 roll on the Standard Banner, or to buy other currency.
Acquaint Fate - This the currency needed to make rolls on the Beginner / Standard Banner. Takes 160 Primogems per 1 AF, which is 1 roll.
Intertwined Fate - This is the currency for the Limited Banners, currently Venti banner. Takes 160 Primogems per 1 IF, which is 1 roll.
Original Resin - This is the "stamina" currency. You have 120 Stamina to use each day, and it regens at 1pt per 8min (I think). You can buy stamina refreshes 6 times/day, each getting more expensive, you need Primogems to purchase them.
Those are all I can think of that you should be aware of. If you like the game, I would advise buying the "Blessing of Welkin" for $5. This will give you 300 Primogems immediately, and 90/day for 30 days. so 3000 Primogems in total. There is also a Battle Pass with a Free track and Paid track. These give you some Primogems and AF/IF, and also lots of various materials. The Paid track costs $10 and basically doubles the rewards, but I think it will reset after 48 days, so only get the Paid track if you plan on playing that long since you have to be doing the various daily requirements to lvl it up. You can pay $20 and you start the BP at lvl10 (if you're lvl11, it won't add 10 levels, it just starts you at lvl10).