You won't be able to delete heroes, so choose wisely. ^^
this, you get 4 slots (if you spend money (BF) you can get up to 10pr. account)
In high levels (lvl+20) commandos who wants to knife, has a hard time.
(stealth level should maxed first
Gunners start slow, but will in a few levels (level 4-6) be the fastest leveling char all thru the rest of the game.
(for gods sake, remember to put the first point in Leg-it, then one in I Eat Grenades, then fill up leg-it.. and share leg-it with your team
Soldier takes skill, and manages average thru all levels.
(CombatMedicine.... CM.. and..CM.. fill it FIRST, and share... you might also want to put one of the first in BlastingStrike to knock those pesky knifers away