Isn't this indignantly digging the hole deeper?
- "Ammo will be more limited, some weapons like smg, ak now only have burst fire."
This is taking away a tactical choice from combat in a turn based game; that's what these games are about. This diminishes [even wastes] the strengths of the mechanics, as the player can no longer choose to conserve ammo, or to risk the expenditure in the hope of damaging multiple enemies.
It would become simply an expensive/ wasteful option to use on a single target; all the more reason to hoard ammo, and to use melee when they can. Also it costs more APs of course—because it takes more time. That means that many PCs will only be able shoot once per round, if they choose to attack, and they will waste bullets doing it. They will no longer be able (with these burst weapons) to shoot at two non-adjacent targets; that
can mean the difference between (them or their allies) surviving or not.
- "It will not be like a shooter you have tons of ammo and enjoy."
Modern shooters aren't real shooters; real shooters limit the ammo, and almost make it a puzzle to survive the map through to the end. Ammo scarcity is not a bad thing IMO, but players who specialize their characters in firearms expect to be shooting most of the time, and might be quite irked by the lack and expense of ammo.
- "And do not forget one thing the enemies also have guns so you don't get overpowered."
To turn a phrase, I think you might have guaranteed they will get overpowered...
overpowered as in outmatched.
- "I am thinking a system like fallout 1, items in shop dont respawn anymore, and cost more."
If the stores don't restock, it takes away from the illusion of a living world. Presumably other customers visit the merchants, and do their own bartering. A static merchant inventory implies that this doesn't happen; implies that the merchants only survive on the player's patronage.
- "And in random encounters you find now less ammo."
Which furthers the aversion to 'wasting' ammo on random encounters.
In the film Mad Max, he had only a few shells for his gun and no clue if they'd fire... which was great for a story, but not usually great for a game. Not if the PC is developed towards relying on a gun; where they start losing the moment they use their last shot.