Used my debit card to purchase on coinbase for year plus with no issues.

Credit card is a no-go. But Coinbase and Gemini (after an initial wire transfer that you have to file at the physical bank) work okay.

My boyfriend keeps getting his cards shut down through them every time he uses it on coinbase.

No issues transferring in and out of Coinbase.

Fairly friendly. Has allowed recurring Coinbase buys without issue for a long time. In the last year they regularly ask basic questions about the purchases, recently being as invasive as to ask what currencies I'm buying at Coinbase.

No issue after filing out correct paperwork moving extremely large amounts.