connect 2 Time Capsules via ethernet

I have 2 time capsules in opposite ends of my house which are currently configured to connect wirelessly, and they do that jiust fine. No problem. I will call them R1 and R2. R1 is directly connected to my cable modem. R2 is connected to R1 via wifi and is configured to "extend a network," while R1 is configured to "create a network." However, when I connect an ethernet cable from a lan port on R1 to the wan port on R2, as the Apple instructions online say, I lose all wifi. The SSID and password and name are all the same - the system works fine wirelessly. There are several reasons I need/want to connect the two via ethernet, not the least of which is that R2 is connected to my Bluray DVD player and to my Apple TV, and trying to stream via wifi is slow to say the least. But I also work all over my house, so I need wifi from both time capsules. The configuration for a "roaming network" given on the Apple support site does not match at all what I am seeing when I use my Airport Utility. So how do I connect these two routers (Time Capsules) and still have wifi at both points?

There is another, related problem. I am also trying to add a 3rd access point. I have already an Airport Express (I'll call it R3). I would like to connect it to the network, either wirelessly to R2 or via ethernet to R1, to extend the network even further out to my motohome. I know that via wifi I can't go R1-R2-R3. R3 has to be within range of R1. But what about if I can get R1 and R2 wired together and still broadcasting wif? Can I then connect R3 to R2? This is only a temporary necessity while I have relatives visiting. Getting R1 and R2 to talk to each other via ethernet AND to broadcast wirelessly is the big deal.