Does this setup appear to be workable at all or do I need to redo it?

I see what your saying...But none of the three valves control the spa main drain. They all control the pool (main drain and the two skimmers).

If there isn't any spa suction line, then there isn't any way to heat only the spa without also heating the pool.

That plumbing is a mess. Replacing it all would be a good idea. However, you should find out as much as possible about what each pipe does before you take it out. My suspicion is that there is a spa suction line somewhere. If there is, it simply isn't plumbed to the suction side of the pump.

Okay got a guy that is going to take a look at my plumbing. He also said that I may have a high limit switch issue? Is this something that has to be replaced or something that may be able to be repaired?