Is that even a thing? I know that with the pc server I host, or any server I have ever played on...everyone who joins has to have downloaded a copy of each mod on the server... how would that works for ps4 players with no access to the Steam workshop being able to connect to said server?

As above said, it's impossible. The engine is different between PS4 and PC, not just steam. So it'll never be possible unfortunately.

Yeah alright, i did not know. I have never played the pc version, tho i might in the near future as some of these mods look pretty sweet. I was just wondering cause i am able to do things like change items and item quality in things like loot drops and beaver dams and such, so i dont know the full potential of things i am able to do on a server setup like i have. If anyone knows i would love to hear about it.

Q) The NPC's swarm the map, how can I reduce (but not remove) them?
A) Modify this line, whereby X is the amount you prefer.
DinoSpawnWeightMultipliers=(DinoNameTag="Human",OverrideSpawnLimitPercentage=True,SpawnLimitPercentage=0.X,SpawnWeightMultiplier=0.X)
▬ NOTE: By putting both values on 0.0, you remove them.

Where and in wich file?

GameUserSettings.Ini

no mods for consoles.