Spoke to a Wen generator tech and he stated "The total rated power of the parallel kit is 3000W (25A).
I have two Wen 2000 inverter generators with the connection panel and use them quite often when we go camping. They work great and I do not notice it being louder when both are running at the same time. If it is louder, it is not by much at all.
This kit has the same connections as the Honda, Ryobi and other parallel kits. From what I researched, all parallel kits are the same. They just join the live, neutral and ground from both generators and feed it to receptacles. There is nothing complicated. I was going to make my own, but for the $50 I paid on Amazon it just wasn't worth it. The construction of the kit is pretty sturdy, I'm using it with two Ryobi inverter generators for RV power. This would be a good solution for non-companion Hondas as you would still get the 30 amp RV outlet. If you're still unsure, Google it and you'll find many others have done it this way.
Yes, but be careful not to overload the generators running too much at the same time.
Yes -- If you look at the 3rd picture in the upper left hand side of the web page, you can see a picture of exactly that set up.
I saw the wiring diagram on a competitive parallel kit (one for a non-Wen, different but similar brand), and although I'm not 100% sure, I'd wager this would work with any 2000w inverter generator that's designed for parallel operation. I suspect this will not fit well on the top of a non-Wen model case though. You might search Home Depot's website for "Generator Parallel kit". There are several offerings which may work.