Yep. That is what we do. We rarely play with the wheel. I find it a distraction. Sometimes we use it just as a side piece but we always start with the river. We tried using the wheel as a start piece but I found it too big. If it was 3 x 3 maybe but 4 x 4 is too big in my opinion. We only bought the wheel as it didn't cost much more and it is good for a change now and then.
You mean put both games together? Yes. From what I know they are identical tile sets. The Wheel tiles have a watermark to ID them plus some will have the Wheel move ahead number on them, You could use the Wheel itself to make teh game bigger and not play the actuall Wheel mechanic.