With custom obj modules, set size and when going to test, set the module to debug so you know how large it is on the map.
I usually go a bit larger to cover more area, however, I also sometimes use a few smaller sized cust obj modules, which would be anywhere from 1500 to 5000. I typically only use custom objectives when no civ objectives are available on the map, or they are are 0 priority (ie: Lythium is like this for civ objectives...a lot of 0 priority civilian towns).
Alive is user friendly, but take a lot of testing to balance the forces, movements, and everything else. With a bit of module tweaking, like priority and size filters, you can custom tailor your objectives and get the activity and troop movements you're looking for.
First thing I do is setup TOARs, then the modules. Leave priority and size filters blank for civ and mil obj modules, this way I know exactly how many objectives are on the map. From there, I start tinkering with the filter settings until I get the objective counts and locations just right.
Once that is acceptable, I'll start adding modules and units, all the while testing it to make sure no errors pop up.
Remember, things are a little different when setting up insurgency type campaigns. That's a whole different setup. You also have to have civilians which you can question, assisting in determining locations of insurgency HQs, wep depots, recruitment centers and such. All the while watching for IEDs, and suicide bombers, as well as the actual insurgent troops. IF the civillians are angry with you, they may pickup a AK-47 when you aren't looking and shoot you in the back. This is my preferred campaign style actually.
Want a real challenge, setup a campaign with three military commanders. One blufor, one opfor and an insurgency commander. Now you have best of both worlds - force on force as well as insurgency to manage.
EDIT: with the modules settings for static troops (high, med, low, and none) far as I understand it, they will be garrisoned inside buildings for the most part. I notice that they will (usually) start moving out of the building for patrol eventually. Try setting to medium or low and test.
Right now I'm using Lythium map (the best middle east map out there right now..and huge!) so I only use CQB module with insurgency. If I use it for my force on force campaign, for some reason civilians will not spawn if CQB synced to blufor/opfor, but seems fine if only synced to ind ai commander.
BTW: include game master module, this way while your in the editor and test playing, you can press Y and you'll enter zeuse mode and you can fly around the map and watch the troops spawn, move, and fight in the 3D space.