Jay I wouldn't worry too much about the EGR system on your 1997. The 1993-1997's are way less problematic than the 1998+ and have a totally different (feedback) system. As far as the ticking goes, you could try running engine flush prodructs (seafoam, GUNK, etc..) I personally would just keep up on oil changes, use a quality 5w-30 and a GOOD oil filter (napa, carquest, purolator, isuzu). The lash adjuster tick comes/goes with these engines.
G/luck
Joel