Yep. You can take the points out of your bank and use them too, although I wouldn't advise it. That's how I lost like 3 million points last time.
I haven't run into any that aren't fun honestly. I'm pretty sure I've tried them all by this point, too.
It seems that way sometimes, but I'm pretty sure it's random. Because I've won rolls on roulette where I bet a million points before. $$$