1) Forcefield
The concept would be something that could be activated for 8 hours. If anyone you share your base with were to spawn into the server, the "forcefield" would become deactivated with a 16 hour cooldown. The forcefield wouldn't make the base impenetrable, but instead a little more difficult to penetrate (perhaps double the C4 necessary).
Nope, just seems... Odd?
2) Booby Traps
Stepping through a wire that activates a nearby grenade. Stepping on a landmine. Walking through a line that shuts a gate that could lock you in a room. An electric fence that shocks you.
This might be cool, grenades on a wire, traps with spikes etc :)
3) Auto Turrets
Automatic weapons that shoot at nearby intruders (see TF2).
Nope. Think more like, open door == Arrow in your face, more like a boobytrap.
4) Metal Gate
Much like the wooden gate, but something that would require C4 to break through.
Probably in the planning already :)
5) Draw Bridge
Exactly what it says (would require water within the main map of course).
Cool!
6) Guard Dogs
Ability to tame dogs/wolves that you could place around the base.
Yes please, its already possible to lure animals near your base. So that they start barking when someone is near.... This just adds a whole new level to it :)
7) Ability to dig
Allowing you to build holes that enemies could fall into.
I doubt the engine allows this.
8) Poison
Ability to place poison onto items of your choice into your own storage crate. If a player were to equip and/or consume this item/food, it would poison them.
Yes, would be cool. Just like weapons that are tampered with and explode when used :D