Donot do the egr delete, unless you want to loose aprox 2mpg, The performance gains are so minimal that you need a Dyno to see the difference.
But the loss in Fuel is felt immidiatly in your wallet..
As far as the cat's yea remove them for fakes and get a good tune. the smog test will never know the difference. only visual test will.
I replace mine with hollowed cats, that have a tube stuffed into them to keep my flow pattern the same as a straight pipe, but passes visual.