OK, so you bought an 8 year old used MH that was repo'd. You have to expect that there are going to be some problems with it. I mean, it probably sat for quite a long time which leads to what is called "lot rot". When we bought ours it had been sitting for a year and a half and it took us 2 years tor get everything running properly. That comes with the territory.
The purchasing dealer has offered to fix the brake problem under their warranty. So what if you need to bring it to them, it's going to be a lot less than if you have someone else do it. If it doesn't work then you are only out what it cost to take it to them.
Get over it and quit trying to micro manage something that you admittedly know very little about. There will be many more small to large issues in store for you with an 8 year old used MH. Trust me, been there and done that.
Keith