What's the most common mistakes the more experienced players out there see amongst the fish that we should learn to avoid during these stages?

1. I often see people making thin calls for a large portion of their stack that will often cripple them if they lose.
2. Playing Speculative hands badly and overcommitting with them.
3. Mistaking chip EV for Tournament EV.


Hopefully this should spawn some conversation even if it is flaming of me. Any other prominent mistakes evident in this level.