Does this have a warranty? The cover broke off less than 60 days.

As you may know amazon guarantees for 30days. However I would bet if you contact the mfg and let them know it only lasted 60 days they would replace it. They don't want to get a bad review. I bought one and it is great!

Can I use this shop vaccum hoses? Try to use 2" pipe and put the vac in another room with multiple hookups using something like this

It sounds like you are trying to put in a central vacuum system. I have no idea if it would work. Just looking at the part makes me wonder about an air seal. Maybe there is room for a o-ring under the cap. If you are handy, hook one up with a gauge and test it.

will it fit a zodiac mx8?

Bob: This will work with the Zodiac MX8 but you will also need to get the Zodiac Pool Systems X77094 Suction Adapter for Swimming Pool. If you do get this you'll need to put a zip tie around the flap's bottom and then a zip tie through that last zip tie and around the suction adapter. Pull the zip tie around the adapter tightly then the tie around the ATIE Vac Lock tightly. Ocassionally the tube can separate from the Vac Lock.

What is the exact inside diameter of the port side?

It is NOT 1.5" for the inside Diameter of the hose port. I asked specifically if someone could measure the ID of the port hole and got the answer that it was 1.5".. it is not. I measured it and the inside opening is exactly 1 3/8". I have been pulling my hair out trying to figure out why my 1.5" pool hose won't fit, and keep getting told 1.5" hose goes with 1.5" fitting. No. What I have is a 1.5" PVC pipe, with a 1.5" PVC Female fitting glued on. Then you screw in (attach) this product (The Pool Vacuum Port) which is a 1.5" threaded male. Then you open the flap and you will see the Hole is 1 3/8" diameter opening. So I went to a pool shop and measured a 1 1/4" pool hose, and it has a Outside diameter of 1 3/8". SO now I'm going to return my 1.5" hose and get the proper 1.25" ID ( 1 3/8" OD hose). Wish the company selling this product would give the simple ID measurement and save so much trouble.