(a) if Feldmann really has a P solution to 3-SAT by reducing it to LP, surely he can demonstrate this empirically, there's plenty of solvers out there for both LP and 3-SAT.
(b) the reduction of 3-SAT to ILP is classical (<a href="http://www.cs.berkeley.edu/~vazirani/s99cs170/notes/npc.pdf" rel="nofollow">http://www.cs.berkeley.edu/~vazirani/s99cs170/notes/npc.pdf</a> and <a href="http://www.cs.cmu.edu/afs/cs/academic/class/15451-s10/www/recitations/rec0408.txt" rel="nofollow">http://www.cs.cmu.edu/afs/cs/academic/class/15451-s10/www/re...</a> are two quick examples)
(c) Just skimming, I don't immediately see any reason to believe that the solutions to Feldmann's LP formulation will be integral.