I think in the case of most documents you sign when buying a home, a) you don't have a choice (except don't buy a home) b) there are way too many documents to read (are you seriously going to pay the notary to sit there for 6 hours?) and c) it's all highly regulated and formulaic. Have you ever heard an anecdote to the contrary, ie someone who was bitten by a hidden clause when buying a home?
Honestly, the best way to do this is to just pay an attorney who specializes in it. They will just tell you what you're agreeing to, and you can actually believe them since they are your attorney. It's not cheap, but not too expensive on the scale of a real estate transaction.
I think this is only the case when getting a mortgage, which involves a regulated third party which is likely going to resell or insure the debt, involving fourth parties.
If you just buy the house like you buy anything else, everything is negotiable.
