metanewbie
100 W
Great questions. I will ask.There's potentially hundreds of rear hub kits that fit this definition. Look for a machined sidewall.
Check with the supplier to see if it is a dual reduction geared hub motor. It doesn't look like one. Weight is not specified. Model is also not specified, so you need to find that out. before questions #2 and #3 can be answered.
My rule? no specs, no buy. Otherwise you're playing roulette with bad odds.
Recommend you spoke a wheel with a light motor that's optimized. That's how you'd get what you were looking for originally. Many hubs have been mentioned which are more suitable than this one which probably has a single gear reduction and is heavier than you wanted.