+1 for PayPal (I had some bad fraud experiences with credit cards (locked, however no money loss) in the past and, compared, prefer PayPal over CC).
Well if I would have to use CC then I would consider it, but preferable PayPal (and at least I didnt find basic support for PP that hard to implement, but I admit that was quite a few years ago already and things might have changed).
Pretty sure you miss a lot of pledges if you only offer bitcoin (which still is a pain in the *** for most people) and CC which is not that widely used in every country.
Anyway glad that you’re working on the pledge upgrade system! Guess there are quite a few waiting to throw more money at you