I have never had any trouble with the aluminum screws included in the FT kit. I did switch to Lunsford titanium screws a few months ago, but that was purely because I didn't want my car covered in blue, and I thought the silver screws looked better. I believe I used the aluminum ones for a little over a year - no problems at all.
I also agree with whoever pointed out that Hitec's customer service is suberb. I sent my two bad servos in to them a few years back, and they replaced them with new ones free of charge.
Josh