One or two piece shouldn't matter. You take the toilet seat off and mount it on the toilet first and put the seat over it. It comes with a t-valve that attaches to the water supply.
Bidet has a direct connection fo the water source with the toilet water tank. Turn back on the valve, the water should flow in the bidet and toilet tank.
Yes, just don't lose the washer or else the water will splash out the back of the toilet onto the floor.
Yes, should have padding
Two people in our household are 300 lbs. Not sure if there is a weight limit, but we have not had a problem. Fort heavier people with mobility issues, there bidet is very helpful.
It really does not unless you use a towel to dry yourself. False advertising!
China, of course
The t-adapter it came with would connect to the toilet, not directly to the water supply valve. If you lost that, you'll have to see what you can get at the store or online. Not sure what the mfg will do for you.
Please reach out to our Customer Service Team directly as they will be able to assist further. They can be reached M-F 9am-5pm CST at 847-458-2334 or toll free 877-339-5214. Thank you, Bio Bidet
The water comes directly from the wall Note, the water is going to be cold. WE are in Florida and so the water is warmer than in our northern home for the summer but still chilly!