After screwing around with Spectator mod again, I realize how dull it is with the teams buying only standard stuff while I have all sorts of mods installed with awesome units and weapons. I was wondering if there is some mod, code or anything I could tamper with to make them buy the mod units. I also get a feeling this is the wrong section, I'm not sure whether this should go in Mod Making, Help or here

A lot of mods come with coustom skirmish activitie using their soldiers and weapons, take a look through the scenes in-game, to find some.

It is indeed, and fairly easy to do.
Go to your CC main folder. Enter Base -> Scene -> Scripts, and you will be presented with several LUA files. Each of these corresponds to one of the game types you play. Open up "SkirmishDefense" with Notepad or another text editor and look for the following lines:

self.WList = { "Grenade Launcher", "Blaster", "Nailgun", "Pistol", "Sniper Rifle"...

This is the list of the weapons the computer can buy. Simply add weapon names in the same format and the computer will spawn with those weapons. Make sure to check the code name of the weapon in its mod folder so that it works correctly.

self.AList = { "Mia", "Dafred", "Dimitri", "Gordon"...

This is the list of actors the computer will buy. Add names in the same fashion as the weapons, and double check the code name.

What do you mean "Code name"? I am currently playing around with the names, but when I try to load the game it pauses on "index.ini *checkmark* Done!" for Spectator, which is what I am trying to modify. I'm trying to give the AI the ability to buy some MDC weapons and the general purpose trooper.

Alright, let's say you want the computer to buy Dummy Blasters. First, you need to find out what the game calls blasters, so go into the Dummy folder, Devices, Weapons. Here the folder is divided into Explosives, Launchers, Pistols, and Rifles, so explore until you find the Blaster's configuration settings. In this case, it is under the Pistols folder. Open up the settings and scroll down until you find this line:

AddDevice = HDFirearm

Then, find PresetName, right underneath that line. The preset name for the blaster is, of course, "Blaster."

PresetName = Blaster

Armed with this knowledge, we then go back to the Scripts folder, as I described in my last post. Open up SkirmishDefense, and find this line:

self.WList = { "Grenade Launcher", "Nailgun", "Pistol", "Sniper Rifle" }

We see that Blaster is not in this list. So, before "Grenade Launcher" we type "Blaster", and the list then looks like this:

self.WList = { "Blaster", "Grenade Launcher", "Nailgun", "Pistol", "Sniper Rifle" }

The computer will then purchase Blasters along with everything else in the list. Rinse and repeat for every weapon you want, and repeat the same process in the Actors line for the same results.

Is there some kind of arbitrary limit on how many weapons the AI can be assigned to buy? After I kept getting errors with just 2 weapons beyond what was stable, I took off 2 of the standard weapons and it worked again.

Really? I did more replacing than adding. Let me check really quickly.

EDIT:
I added two weapons to the default list, and the game ran fine. I'm going to ask the inevitable question about your syntax now

Make sure that:
There are quotes around the name of the weapon ("Lolgun")
There is a comma and space after every weapon except the last, with just a space ("Lolgun", "Wowgun" })

If not, I have no idea. Never had a problem except for typos in the weapon names.