I would get rid of the rifle and the rifle ammo. If it is only you and three others, you are going to want to evade instead of fight, as you might be outnumbered and the might have vehicles. Ditch the medkit, if you get hurt, you are dead either way in the desert. Ditch the flares too, you don't need to attract attention. Take cover during the day and travel at night. Don't fight unless you get cornered.