If you have an extra corrode that deals 1 dmg, is it a 1 time thing or dot? The rules just say deal 1 damge not deal 1 damage each upkeep, from what i found?
You answered your own question, but yes, each additional corrode exceeding armor value deals 1 direct damage (once). You only place Corrode tokens up to the amount of armor the creature has (e.g. up to 3 Corrode tokens on a creature with 3 Armor); beyond that, instead of placing a Corrode token, the creature takes 1 damage.
If a guard is pushed into a wall does he lose his guard and if they have a defense can they dodge or is that only if there is a gamage barrier or passage attack?
"Pushed into a wall" is a "bash attack," which is a 3 dice Unavoidable attack. It doesn't deal any condition (such as Restrained or Incapacitated) that would take away a Guard marker. See "Bashed" in the Codex.
Firefist brawler says it deals a burn when you roll critical damage not deals critical dmg. Do you have to deal the critical dmg or just roll it?
It says "roll critical damage" so no, the critical damage doesn't seem to need to be dealt (e.g. Veteran's Belt with sufficient armor would cancel the damage but not the Burn token) - but I assume we'll see this in the next FAQ ("Official Rules Supplement").
