The Thai MFA site says:

Foreigners entering Thailand under the Tourist Visa Exemption category must possess adequate finances for the duration of stay in Thailand (i.e., cash 10,000 Baht per person and 20,000 Baht per family).

so I assume that if/when asked you would have to show this amount, or the equivalent in some other currency?

People do get asked.

You can grind through the TV forum for experiences.

http://www.thaivisa.com/forum/topic/...when-entering/

Other oddball requirements? Too many to list, and they change daily. If you are Rohingya arriving by boat you may experience different oddball requirements. "Push 'em back, push 'em back, way back".