Though there are no other cloud hosting providers that give you VPS with public IP and 24GB RAM for free. Oracle did shutdown my VM like 2 times in 3 years, but considering I paid them $0 it's borderline awesome service.
Sounds like you got further than me, they simply permabanned my payment information (also cannot complain too much since i didn’t pay a dime either, but seriously?!)
IDK, their support is pretty responsive and the only requirement they have is that you must sign up using actual credit card and not some prepaid / debit one.
No I did not, but I dont host my mail on their servers either. I still used it quite extensively and it's far more reliable than 99% of cheap cloud providers.
I mostly use them as my personal build server and VPN.