Honestly i have not tried moving btc into cash on River. But you link your bank acct, so should be no harder than vice versa. I just dca direct from our bank to River, then move to self custody after a certain amt. If you set up dca, there are no fees, i love it. And they are based in Austin. I have called them several times to ask a question, and a helpful human answers. Might be important for a newbie. Just last week we moved some cash from a crappy savings acct to River instead, i'd rather earn interest in btc than a crappy 1-3% cash. Oh, and i really like that you can withdraw with lightning too. Pretty convenient. All their limits are posted on their site, i just havent run into any issues with that, so not sure the amts.