I’ve been in that band. Imagine Rhythm Stick being counted in as per the record, only for it to jump up 30bpm or so - I just can’t play that fast and told him so once, in a not very subtle way, which, on reflection, I’m not very proud of.
Wow! Love that playing. US church music seems a completely different animal to what we normally have here (I understand that they're paid gigs, from what I've heard), that is completely joyous and funky at the same time. Who wouldn't want that to celebrate one's faith?
It could be legit, but given the amount of scammers and general ne'er do wells out there, I think you're right to feel twitchy, especially given the amount involved. If I wanted the bass, I think I'd organise a couple of days away and pick it up in person for cash.