I don't know how much is too much, but I don't believe I have ever seen a "habitat post" on Pond Boss where the replies were, "That is too much habitat!".

Further, somebody used to post an illustration of the habitat that Ray Scott was going to place in his next bass pond project. The planned amount and diversity of habitat was impressive!

Perhaps you could even make some of your habitat "variable". Put in some fluffy cover with a float and a rope. Leave it in during spring and summer for your forage fish to spawn and grow. Pull it out in the fall so your predators can gorge on the forage going into winter. Rinse and repeat.