I need your opinion...

I'm making a map, similiar to Zoator TD, but more Heroes, less TD.

You run around killing creeps in a large world while you build your TD at the same time... My problem is that if you are only 2 people in the game, it's too easy, but when you're 6, it's way too hard. Anyone know how I could balance this in a good way? You also get gold for killing the other players heroes.

The second thing, is if there is a way for a unit to spawn with random items that he can sell... I got a "building" with a character model that despawns at night and comes back at morning with fresh loot, and I want the loot to be random.

Try manipulating with handicaps. For example: handicap for creeps = 30*number of players. With 1 player creeps will have 30% hp, with 2 players 60% hp. With 6 players they would have 180% HP.

Would have to make it the other way then, since its too easy if you're alone in the game, and too hard if there's too many.

then handicap = 200%-(num of players*30%)

I did 105%-(5*(amount of players)), so its 100% if you're alone, and 75% if it's a full game.