Boomer, I always recommend that folks should have two or three smaller vs one large one. You should be able to raise some pretty nice LMB in the 3/4 pond if ya get the right forage started and manage it correctly. The smaller the BOW the easier ta manage. If you keep them separate you could use the small one for either a forage pond or a put and take with CC and HSB or do like Bill D and put everything into it. A fun pond if ya will.
As for the tires, I drove fence posts in what would be about 8' of water. I cut holes in the tires and stacked 6-8 tires on each post. I spaced the posts so the tires almost touched the tires on the next post thus making a tire reef. Then I attached a goose decoy to it so everyone could see where to fish.
As to the pier, I can't give much input except to make it at least 4' wide and a T shape with the end being more like 6x8' somewhere ya can put a couple of chairs and have 3-4 people move around comfortably. If ya have kids maybe a diving board.
Not tryin ta tell ya what to do but some things to think about.

Do nature a favor, spay/neuter your pets and any weird friends or relatives.