No need to apologize. You can always do a search to see if your question has already been answered. Sometimes there are different nuiances to your question though and you still need to post. That's the whole idea of these forums. :)
As for your propagation questions, here's some helpful sites.
You might find this helpful too. Pruning climbing roses:
Not sure what you are asking in Q. #2. I think you want to know why one does better then the other. If so, it could just be a hardier rose or one is in a location that isn't as sheltered as the other one. If they are the same rose, it could still be the location or genetics. One never knows for certain. With this site you can search to try and get more info on your rose 'America'. Put in whatever features you know.
Once you have the full name you can search for more info at www.google.com
Hope this helps,
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.