A "salt" pool is a chlorine pool. It just uses a SWG and the dissolved salt in the water to generate chlorine.
A "chlorine" pool also has dissolved salt in the water, sometimes at higher levels than you may think.
No. Remember, all pools have salt to some extent.
No, same concept as above.
Depends on the pool, and each setup is unique. I have an efficient system that works well at 1,000 rpm. That's enough to operate my SWG, skim, circulate, and filter. I run my pump 24/7 and it consumes ~75 watts. This equates to ~$6/month in electricity to operate nonstop.