Well, I have manuals that come with my coach when I bought it brand new in 4-03. Just about every appliance that is in the coach, and the chassis manuals which includes a Caterpillar maintenance, Allison 3000 manual plus many more.
Personally the only thing I have looked up on the manuals are when to maintain oil changes and document when I do them. That way I know that oil changes have to be done by certain amount of miles or one year which ever comes first.
I also had a problem with a limit switch on my Suburban furnace. Found the problem and got it fixed. Other then that the coach has been pretty good so far. Hope it stays that way.
I have noticed that if you use the coach a lot, you have less problems then when you let them set for long periods at a time.
Congrats on your new coach, the Friendship is a nice coach. You got to remember that any coach, any brand high end or low end needs some up keep. They are just like a house on wheels which bounces around on rough highways and things do get lose and need attention every so often. That is just part of RVing.