Retail speculator here. Re 2 it's often quite easy to demo on thinly traded markets - I'm more familiar with crypto. Say the spread is 81.00 buy, 81.03 sell. Put in a limit buy at 81.00 and watch someone/something immediately outbid you ate 81.01. In the short term that kind of thing is done by algorithms but there are humans behind it and doing it too.

There's quite a lot of other game playing going on also.