Nice application!
But that's not a programming question. Not a question, even.
So I change its type and move it to exhibition section.

Very good. I compared it with an other pathfinder program http://www.robotacid.com/PBeta/AILibrary/Pathfinder/bfs_demo/index.html and it seems that your program is a (allot?!) more efficient. It feels really analog.

I have updated it now so you also see what the fuzzy logic controller are doing..

How you handle more than two inputs is to multi stage with more than one FAM.

FAM 1 has two inputs and outputs its result which is combined with another input in FAM 2 to output the final result.

It sounds clunky but with traditional sets of fuzz rules you increases the number of rules to the power of the number of inputs. With multi staging FAMs adding a new input just adds another FAM, a lot less processing and memory usage.