Hi, first of all I really love this mission so this is meant as constructive criticism to help. I have played over 100 hours of just this mission so you can tell I really like it and want to see it grow and improve. I voted for this on Makearmanotwar as my favourite mod.

I know that player needs can be disabled but I think it would be better to see the time spent on the eating/drinking/gathering/stealing part of the mission instead spent developing other areas.

This is a military mission, not a survival apocalypse scenario like DayZ/Wasteland etc.
You play as a member of a military team sent to the island. I think it can be assumed that you have food/water with you when you arrive.

The constant need to gather food and water for yourself seems very out of place.

If you focus on the missions to liberate the Island you can take over control of the whole place in around one in-game day.
Even if you spend time sandboxing, just messing around in between missions, you will still complete the scenario in a few days. I can't imagine one game of WLA lasting for an in-game week, that's forever in this mission.
So there doesn't seem to be any real need for your guys to be constantly needing to scavenge food etc It's not like they are there for months and ran out of supplies.

Also there are literally thousands of houses and shops all over the island, it's not post-apocalypse, everywhere still has running water, so why are you/people dying of thirst because you can't find them a barrel of water? It just doesn't make any sense to me in the context of this mission.

Why not change the system so instead of survival style scavenging for food and water to focus on having to scavenge weapons/ammo/explosives crates, medical supplies, fuel for the rebels. This could involve missions to raid CSAT camps/ ambush supply trucks for equipment and then distribute it to the rebels. This helps to upgrade the AI rebel troops that spawn at camps and patrols. That makes much more sense I think and fits in much better to the mission story where you are special forces trying to coordinate a rebel response to the invasion.