I've been forum lurking since I bought the game.
I have a few comments to make:
First, excellent work on the mod, I've done alot of modding myself and know what a pain it can be, especially if it's a foriegn game. Second, I'm glad you picked this game to mod despite it's condition since I'm a Jagged Alliance fan going back to the original game. Don't bother trying to do model making unless you plan to do it professionally, it takes a long time to learn and unless you're getting paid, too much time imo. However if you really want to learn for kicks, (like I did) look for blender as a powerful but not user friendly program, or sketchup as a user friendly but limited program. Both are free. Far better programs are available, but most cost big money, from hundreds to thousands. You'll need a good computer too. :)
I disagree with your feelings about pistols, sub-machine guns and shotguns. You can solo the game up to the road to the airport using little more than a sub-machine gun and shotgun combo. Put a silencer on your already quiet pistol/SMG and you can plink enemies to death from a bush or grass without giving away your possition. As long as you don't get too close, they enemy will look around but never see you as you kill them. additionally, all SMG ammo will drop often enough that you'll likely never need to buy any. Sooner or later you will have to move to a location where you get spotted or you might make a mistake while sneaking around, and find yourself getting swarmed. This is where shotguns and grenades come in. Shotguns rock at med and short range. Take one single torso aimed shot per turn, and you should always hit. At point blank you will destroy unarmored targets, and knock back/stun armored enemies. At medium range firing down a narrow kill zone, you can hit 2-3 targets per blast. You might do little damage if you don't break their armor, but when this happens it hits them for huge stamina loss. Get yourself behind a barrier and pop up taking one shot per turn as they rush in. When you have 3-4 in close proximity, grenade time.
A few requests:
Make your mod available for the harder difficulties please. In easy, the number and quality of troops the AI sends to attack you is a joke. You -never- need to do anything more than let mercs hold your territory for you, and you can go with a 2 man team through the entire game. Additionally, arm all enemy troops better, and have them drop fewer weapons if possible. Put the merc hiring costs back to the original numbers, so the player actually has to worry slightly about finances. I know Venom is super cheap for her skills, but every jagged alliance game has one cheap super-soldier you can get early on. Add a base of 5 or 10 to enemy camo value so you can't always pick them off at long range all the time. Maybe 20 for soldiers. Increase the size, quality, and frequency of counter attacks if possible.
General information spewage:
I like what you did with the ammo, but would like to point out that 'AP' rounds for assault rifles in the normal game are FMJ rounds. The standard FMJ round used by any rifle that fires a non-pistol round has good armor piercing properties which is why the basic game only has HP and AP rounds for high powered weapons. BUT (yes gotta get a but in there) some companies do produce steel core ammo which is extremely expensive, rare, and in some cases experimental. It makes sense that you could seperate these from other FMJ rounds, but I don't think they'd do less damage, just cost a -ton- and be very rare. The biggest problem with most of these is that it's hard to get acceptable precision in the manufacturing process to make them on a large production scale, and they have a high dollar pricetag per round. Also, as one would immagine, this ammo is illegal in most places so there is little reason for companies to produce these without a market for them.
The caseless ammo should all be very expensive, of the AP variety, and not give a negative damage modifier since that ammo is special purpose AP ammo. There should be no HP or normal variations, as they don't exist. These are ONLY made by a couple companies for specific military customers. The dictator could be one of them, possibly his elite troops.
You mentioned you were working on a red dot sight, one already exists in the game. :D A 'possible' solution for your dual ammo type weapon: make the assault rifle with the primary ammo type, then a special attachment grenade launcher that fires the secondary ammo. You probably already tried this, but if not maybe this will be a helpful comment.
HP ammo?! This is a big gripe of mine with all JA games. I've never heard of HP ammo for any military rifles. 'Soft point' or 'deforming tip' ammo is as near as I can tell already factored in, which is why 5.56 ammo does as much damage as it does next to the much larger 7.62 ammo. The tip bends over after penetration causing the bullet to tumble. Other small rifle rounds also use this. If you try to use an actual hollow point round similar to those available for pistols, it will come apart. New flangable ammo is being developed that would in theory be similar to HP ammo, but as of right now, I just don't see any ammo that really does what HP ammo does that is used in anything bigger than a .22 rifle.
AP ammo for pistols and SMG's also makes me scratch my head. There are a variety of different types of ammo designed to defeat body armor, and some pistols with high muzzel velocity are inately able to penetrate level one (as defined by US police forces) and in some cases level two body armor. Teflon and glass coated bullets do NOT show any real improvement in penetration, but reduce wear on the weapon barrel. The pistol rounds that have the best penetration are steel core rounds, extremely expensive and in most places illegal. Again, I don't see them doing any less damage than a normal slug however.