I have completed my first MiB terror mission yesterday and i have some questions/suggestions.
1) I was surprised to see that a heavy trooper carries a simple rifle. It leaves not even a scratch on flying suit. Other MiB soldiers have shotguns and similar weapons. What they are supposed to do with this? Bring my soldiers to laugh? 
Yeah, I'm aware of the problem... But i don't know what to do about it. If it was OXCE, no problem, you can define a different deployment for a different race (because mechanics-wise, early MiBs and late MiBs are different races with the same missions).
What I could do is give them separate ships, missions etc. But that's a lot of work which I really don't want to be doing, since I don't really develop the FMP any more, except for small changes/bugfixes or because I have the resources. And this would be a really inelegant solution. I guess we'll have to live with
some of the MiBs carrying weaker weapons.
The same applies to aliens. Plasma Caster, Plasma Pistol, Alien Laser Rifle etc. are useless against good armor. It's ridiculous. The aliens supposed to be dangerous, not laughable. Only weapons with >40 damage can do any harm to flying suit, but only 80+ weapons can be considered as dangerous (weaker weapons need a lot of luck).
Alien Laser Rifle is an early crappy weapon, yeah. Which still can kill you easily if you're not wearing a Power Suit. The Plasma Caster is not a crappy weapon and indeed it will kill you unless you wear a Power Suit. Well, Power Suits are neat, eh?
To sum up, the only way to make all aliens dangerous to humans in Power Suits would be to give them all Heavy Plasmas. Which would be really boring and also give you way too many HP clips.
So instead I've decided to keep the weaker weapons, but in limited quantities. Plasma Casters are mainly used for self defence by non-combatants like Navigators, and the Alien Laser Rifles are... well, if you're an alien trooper with a bad luck, you get stuck with an Alien Laser Rifle. War never changes, even if you're from Mars.
Besides, most of them have grenades. Which can screw your heavy armours up.
2) Perhaps a general Openxcom question. Why the aliens throws no grenades? I have changed turnAIUseGrenade to 0, but this doesn't help. They are ignoring the grenades completely.
They don't. I mean, they shouldn't, and in my experience they use the grenades normally. Maybe you're especially good at denying them grenade attacks?
3) Shotgun-like weapons are useless. They are short range and are only good against enemies with a low armor (auto-shot is more effective).
Take these "useless" weapons from me and I'll bite!
Shotguns are the best, when use correctly. It's just that not everyone uses compatible tactics. I'm not really heavy on them either, but I know many people consider them
too good.
4) Laser/Gauss weapons are obsolete, if there are rail/plasma weapons and rail weapons can be researched easily (i have finished the research in august).
Good work! It usually takes much longer.
5) Melee weapons are almost useless. TU cost ist comparable to normal weapons and a damage is not really better.
But the cost is rarely above 10 TUs.
Yes, they are situational weapons, but I believe they can be useful. A knife only weighs 4 or 3 units and it can save your life in a close encounter, so it's often a good idea to take it just in case.
BTW did you know melee attacks don't provoke reaction fire? So using a knife is sometimes better than, say, a pistol.
6) Dogs are OP. They are very cheap and can do 40 melee damage (only 8 TU = 400 damage/turn). The rifles must have alloy ammo to do the same damage. 20 damage were more realistic and perhaps 12 TU/hit. Price must be 20000-30000. They still remain very useful, because the dogs are very good scouts and they can save the soldiers from be killed.
I'm a bit torn here, but at least you can't take many of them (except in base defence) and they prevent you from taking tanks, so there are associated costs.
To be honest I don't know how to balance it further (without getting rid of the dogs altogether), so suggestions are welcome.
7) Tanks are almost useless. They are very expensive and are not really better as soldiers with a good armor. Perhaps the X-Com Sectopods can be used, because they are very well armored and can't be destroyed so easy. For the price of one tank i can buy a lot of dogs or rookies to train.
Then by all means do so. Nobody's forcing anyone to use tanks. But they are vanilla assets and I'm not deleting them just because some people think they aren't good enough. Actually, my tanks are better than the original, so I don't know what else I could do without making them OP.
Besides, an X-Com unit without a tank is usually a unit with way more casualties. They don't matter much game-wise, but I'm not sacrificing the lives of my men just to save a couple dollars, which I have way too many anyway.
Difficulty. The game is too easy even on superhuman. In other TBS you can lose easily on hardest difficulty levels (e.g. HoMM, Eador, ...), but not in X-Com.
That's how the game is written. Blame Mr. Gollop and Co.
I could definitely crank up the difficulty to some degree (more aliens, better aliens), but the FMP is not a total conversion, it's more of an add-on. So basic things stay.
You'll probably like my next project better in this regard, since it's pretty heretical in many ways.
- unlimited money (workers + rail cannon gives me ca. 2M/workshop/month and i have 4-6 workshops/base).
True, but see the previous point.
Besides, I'm not really interested in the game's economy. X-Com is a combat game, so I don't really mind not having to worry about damn columns in the damned books.
Because you can't really buy yourself a win here, you still need to do everything yourself - money primarily translates into more bases, which I think is okay.
- harmless UFOs (plasma beam and the only threat is a battleship, but a tormentor can shot a battleship easily down with rail cannons). In X-Com 3 even a smallest UFO can do damage.
What would you like me to do, put a Battleship-class cannon on every Scout? Some UFOs are dangerous, other not so much. That's just how they are. Again, I could change them, but that would be a major change, beside the scope of this mod. Plus, I would have to design it from scratch, since it's rather tricky to balance.
- ground battles are easy, if you are careful (smoke grenades + dog scouts = win)
Maybe you just need a harder game, try
X-Piratez 
