sure its safe, but is it legal? :P
removing a cat can really free things up as far as restriction. what good is your 2.5" exhaust on a bottlenecking cat? but theres a give and take for this. off the line you might suffer because there is no low end back pressure. but high end will gain because there is a lot less restriction. why get rid of a cat completely? get the best of both worlds with a decent high flow cat. still retains some backpressure but flows a lot better than stocks. just my 1/50th of a dollar