Bugs:
The friend of mine hosting occasionally had his camera completely bug out at the end of waves. This has been reported before.
Sometimes, waves will not end properly, and will take quite a while (5ish minutes) to progress to the next one)
Sometimes, enemies won't actually approach anywhere near the Bulwark, and you have to hunt them down, because they just stop moving.
When trying to put down walls and such, they'll instantly K/O teammates if they touch them, making building anything quite difficult.
Your camera view is far too close to the objects you're playing down, making it similarly hard to position them correctly or, say, avoid killing teammates by running into them by accident.
There is no way to reposition barricades. Not sure if bug or feature.

Suggestions:
As it is, fifteen seconds between waves is not enough to do -anything- whatsoever. You barely have time to revive a friend and maybe put down one wall. Not only is looting mostly pointless like this, but it makes building up your position and scavenging for ammo far harder than it should be. This led to me and my friends intentionally taking advantage of the bug where the round wouldn't end to actually get anything done.
There is absolutely no way to select your location. This means that you can often be put by, say, the ocean, where half of the ammo crates will spawn in the water.
Since you start out with absolutely no armor whatsoever and getting it is nigh-impossible, you are quite vulnerable to easy one-hit-kills at the start. This discourages people from actually looting or doing anything outside of their defensive position. At least give everyone an Armor Level I vest or somesuch on spawning. That will make for far less fustrating gameplay.
There should be some sort of delay between the map loading in and the mission starting, or even some sort of mission customization screen, like Dynamic Recon Ops. As it is, about half of the people I play with have difficulties in the first thirty seconds or so as Tanoa actually loads in, all the while, the game is going on.

I may add more to this later. As it is, it has the makings of an extremely fun gamemode, but it's hampered by a few things that can make the gameplay incredibly fustrating at times, or not fun at all at worst.

Edit: Clearer documentation on how to change things like wave times, whether Zombies are enabled or not, and so on would probably be good for those of us not technically inclined or wise to ArmA's scripting system.