As Crashmaster stated, the current Integrity system heavily favors cube shapes in order to maintain positive integrity. As you likely already know, negative integrity means systems will blow up if you are hit by a weapon (even if your shields are up).
In regards to how to handle things like salvage beams, 20 blocks in a line is the max you should do (not only for good mining power, but over 20 means a very high possibility of negative integrity). Additionally, integrity is based on grouped modules, not the overall module count. This means that, for example, if you have a waffle array of salvage modules with 20 modules per line, that means each line of modules has it's own integrity calculation, as long as none of them are connected to each other.
And, yes. Integrity is very broken right now. People can't even make Warp gates because of integrity the way it is.