I see what you are saying, but I knew nothing about boats! I knew how to live on one, but wasn't sure what was a good or bad boat. The survey showed up the steel work as being good, and the engine survey told me that was ok - OK so I knew a BIT about engines, but only motorbike ones.
Also, having looked at a fair few boats in breakers first I could spot the huge variety and what was and wasn't ok.
Its possible to get hold of the BSS. My policy on wiring (which I know nothing about) is: if it looks a mess and you can't work out where the wires go (even from the engine to the board) then there is trouble. If connections aren't done properly (ask in the electrical shop how to connect 2 pieces of wire) then thats a good sign.
There are tell tale signs. My boat isn't upmarket by any means, I bought what I could afford, and it was the best I saw for what i could afford. At the end of the day I knew what sort of thing I was looking for, and also knew I wanted to understand how it worked (where the water came from, where the gas pipe ran, how to fix the electrics), so I could work out where a problem was when it went wrong. I'm now making it so I know about these things.
I think it really depends what you are looking for, and if you know that, its not so bad. Besides, its quite good fun by all acounts - especially looking at different boats on the inside!