@Eddlm First of all, I wanna personally thank you for taking your time in writing such a detailed reply to the topic. I'm flattered you noticed us! Been a big fan of your scripts tbh. Appreciated, mate.
About your concerns:
-Survivors/NPCs: What we have in mind atm is to bring a whole new experience to GTA where you are not the only one hunting survivors/bandits/zombies, but also being hunted. Holdups and bandits trying to steal your loot is also planned, although it's not mentioned in the topic (there are a lot of features we are planning to add to the final version that haven't been revealed yet, we wanna surprise you guys All of them can be found in our Trello ). I'm not a fan of RPGs where you have to find/talk to inactive npcs, standing still there for you to interact with and ask for favors or quests (which is also considered a planned feature), just what you mentioned. But yeah, I like what you are suggesting, random encounters or maybe not that random, you just run into them fighting for the same supplies? Annotated.
-Zombies: We are trying to focus on a complex AI, not just zombies wandering around. We want them to chase down the player and also be hard to kill with melees, so the player has to think about it twice before engaging them. We would like to add quick time events to the experience, but I feel it will be a pain in the ass to implement. Hordes of zombies may be added if they don't have a big impact in performance. I'll write down your suggestion as well. I'd like to see zombies being distracted by a flare, allowing the player to sneak behind them. Or being attracted to nearby gunshots of other survivors as you describe.
Regarding the police and military, it is also planned to add different factions (friendly/hostile) to the world when we have a stable release and make sure the basics are working properly so you can expect that too.
We will definitely consider your ideas. I have already added all of them to the Trello. If you wanna take a peak, you are more than welcome, just text me.
Thank you all again for supporting this project! We are very grateful and looking forward to bringing something special for all of you to enjoy Stay tuned
P.S. I'll try to be more active this year