yes very true but the spawns are around that area so they can break the door at any point so i suggest not using this spot unless you are really good at the game

You'll have to know when to close the door to prevent that kind of dmg, avoiding the husks from afar is rather easy regardless of the door opening, but this isn't the only spot in the map to use, you can kite or just use rens spot

yes true but the siren will take a fair portion of your health then you wpulld have to heal and thats just dead if a husk is shooting at you

lvl 6 support easily destroys them since shotgun penetration

what if double fleshpound come in and a siren is behind them and they destroy the pipe bomb? your pretty much dead on round 10