Here's a few thing you should know if you want to play this:

1- Firefights are good ! if you hear any near you, go and loot the bodies for intel or items
1.1- Intel is always useful. it can be found on computers in ennemy bases or on officers
1.11- officers with intel will always be wearing a red beret to make them stand out.
1.2- Weapons, NVGs and grenades/explosives should always be looted for sale or usage.
1.3- save yourself 6 pair of NVGs, one being for your own use and the rest for a task.
2- Hoard and keep any antimalirium, as you'll need them for quests later on (you can either buy them or steal them in hostile bases/buildings)
3- silenced weapons are your friends, as they allow you to pick off your ennemies without turning an entire base's worth of them on you at once.
3.1- you can find a cache containing an ASP-1 kir at 041 022 along with a scope and an RPG.
4- Find and keep a rocket launcher close to you at all times, no one likes kajmans or orcas.
5- vehicules are precious ressources, don't abandon them in the middle of nowhere, or you'll run out of vics very fast.
6- Sales should be done via the stashes to gain relations with the syndicate
7- If you possess the IDAP DLC, you can stash weapons inside of quads, and store the quads inside of vans. the weapons inside the quads will not be detected in this manner