I'd keep Nelson, at least for depth unless our rookies are outperforming him. He's had good production here and plays like he wants to win. No lazy route running going on. No problems learning how to catch.
Gates and Salas are out.
Otherwise, I don't feel like I've seen enough of the new guys to pick 3-4 more. I am mixed about Hill. I don't think he will pan out but I would hate to see us invest so much play time in him only to see him mature in that third year and hit his stride with somebody else. I'd at least keep him somewhere in the organization unless our rookie class is just incredible and we don't need to waste time finding out what Hill could do just to keep what we know he can do.
The Jets currently have 12 wide receivers. Half of these are not going to make the rosters. Which six would you choose?
For me, it's:
Decker, Nelson, Hill and Evans on the outside
Kerley and Saunders on the inside
Obviously, we have to see it on the field. Still, if you want to guess now, your list is probably right. Ford is a wild card based on avoiding injury. Enumwa is PS but could outperform Evans, Hill or Nelson. It would be a good problem to have.