co ulysses waypoint issues, Is it a bug or ? Options

[|2usty]

Ok Cheeseh i'm a bit confused here, i've waypointed this combat map and i'd like you to take a look at it for me please.
The issue that i have is that the wallstick and ladder climb waypoints are giving me a headache...the ladders are still no good when it comes to skulks & gorges, i'm not sure about the rest. This map in particular is in a pit and has only two paths out if the aliens spawn directly beneath the hive: a ladder and a vent (which starts off closed with a grate) i tried waypointing the vent as they didn't manage with the ladder and even after knocking out the grate blocking the vent they still seemed to have trouble. After all this i tried to create a wallstick path out of the hive pit but they wouldn't even mount the wall, is it possible that the ladder and wallstick waypoints are the issue here and nothing else?
One more thing i'm confused about is the vent itself...am i supposed to put in an opens later waypoint behind the grate because they arent biting through it themselves.
Here is the waypoint file:

[|2usty]

Ok i'll have a bit more of a play with the ladder waypoint and see if i can't get it to work. What should i do with the vent though, is there something i can do to get them to bite through the grate or is that a coding issue?