Superior Pump ‎91250 1800GPH Thermoplastic Submersible Utility Pump

Yes this pump comes with the adapter needed to attach to the garden hose

The pump itself fits a garden hose nicely. You can buy the attachment package listed next to it for the converter piece. It only came to around $8.00. It also comes with a larger hose. I didn't need it for my spa but if you need to empty a washer or bigger pool it seems like it would come in handy. Hope that helps

Not really sure it could be mounted, but it does still draw when tilted or on its side if submersed if part of the bottom is in the air, I would think it would suck up too much air to make it useful

As long as there are no chunks of solid stuff in the water. It doesn't take much to plug it up. I used mine all summer to water my lawn and gardens out of my Koi pond and it is still going strong as long as I keep it off the bottom so it doesn't pick up stuff other than water. It comes ready to use if you are using a garden hose off the output end.

Use it to pump out a pool cover full of debris without problems. This has a plastic filter at the base which keeps items large enough to clog it from entering. Dirty water and small algae and particles not a problem in my experience.