What you're describing sounds neat, but very out of scope for a game of this type, even out of scope for a deeper Jagged Alliance 2. Impossible to balance and suddenly now every map needs to be designed so that none of these strategies is too effective, except sometimes they are so people can still use them. In practice this will lead to situations where the player just throws smoke grenades everywhere and maxes out their Melee skill, and clears every map without ever being shot. And every map will have to be built as a set piece with "Should we allow this, or should this map be very windy so that won't work here?" It would turn this into either a steamroll with one tactic that dominates every time, or less of a combat game and more of a puzzle game. I like having some tactical options of course but "more more more options" often devalues strong gameplay.
Strange, I do remember several occasions in Jagged Alliance 2 where I used explosions to get an alternative access point, cause if I went through the main door I would get shot up badly. Sneaking and backstabbing? Several times.
In UFO:EU you could use the blaster launcher to make a hole into UFO's so you would have an advantage. How often had I used plasma rifles (or an auto canon) to raze a wall to kill an alien behind it. UFO:EU also had smoke, breaking LOS.
In old games a lot of these things were already do-able.
Sure it does need balancing. Blaster launcher in UFO:EU were balanced because you needed rare resources (elirium) to craft them, and elirium was also used as fuel, so you didn't want to run out of it.
Is or was that all more of a puzzle game for you?
If smoke grenades are to powerful, you just make them more rare (also grenade and rockets), on the plus side this is absolutely believable in a post-apocalyptic game world. Try to keep spamming things you don't poses.
If Urban Strife is really just CQC it would be pretty wise to max out Melee skill. Cause you free up more resources for other things than on ammunition.
Honestly you need QA for this, people that are payed for to look for weaknesses (exploits) in your game. Everything can be balanced, if you are willing to do it.
Sure if you are on a tight budget it may be more profitable to scrap things, stream-line things. But yeah in my eyes being a profitable game does not necessarily translates into a good game.
I am still heart broken by the thought how much money game companies have to spent on games and how much less it was in "the golden era" (XCOM:EU, Jagged Alliance 2, Fallout).
Imagine they had access to that kind of money, I wonder what they would have made out of it.