There have been requests for death penalty and i, personally, wouldn’t mind it. I even suggested one in here: Death Penalty When Dying
Yes, teen shouldn’t be able to carry loads of weapons and gear. The initial 50 slot inventory (with Carry Capacity lvl2) was more than enough but people wanted to be cargo mules and inventory limit was increased, twice, to the current 96 slots/units (with Carry Capacity lvl2). And even now, some people want to carry even more gear.
The current state of the game is very realistic and i love it. It sends the message of player not being the top dog over fast. However, the considerably harder difficulty doesn’t fit well with many people.
Like i said above, to sprint “a bit more”, Stamina Amount skill is for that. If the skill is maxxed out then you have to accept that.
It’s like when asking for your weapon to hold more ammo in the clip. For that, there are mag extension mods.
E.g does it help when i say: “It is VERY IRRITATING that .50 cal holds 10 rounds. And i request 2x more ammo in mag by default.” ? 
I don’t think so. With 5* mag mod, i can bring the round count to 18 and i’m happy that my weapon holds more ammo over base level, despite the final number not being a round one.
GZ is designed as a slow progress game, hence the limitations on movement and no drive-able vehicles in the game. It’s something to keep in mind. If you can’t stand the slow progress/movement, then perhaps GZ isn’t a game for you.