Originally posted by NorCal DC4
Yes, all of the parts you've mentioned, in concert with over-inflated tires, can lead to an abrupt, harsh ride. I'd check tire pressure first, as rediculous as it may sound.
IMO, I doubt the LCA and subframe bushings have gone to pot in the span of only 5 years, but then again, if they salt the roads in winter... perhaps they have crapped out..
What are your plans for the car in the long-term? I ask this because it affects the solutions I'd suggest.
I will however share my intital experience with my DC4... maybe it can be of help.
I bought my DC4 with about 95K miles on it in the fall of 01, and the bushings on the front subframe and rear LCA were in fine shape, but I did notice a fair amount of body roll and a general lack of firm damping. This ultimately was due to largely shot shocks...:chuckles: The bumpstops were doing a large amount of the work of suspending the car. 
h:
I wound up going ahead with my TEIN Super Street Coilover Dampers and my 16" 5Zigen wheels, which have helped the body control immensely. On their least-firm setting, they are pretty civil in terms of ride quality... but otherwise, they are designed for maximum performance, specifically in fast cornering and overall grip. They may not be the best solution for you.
So there ya go. 
These are brillant handling cars, with the potential for obscene amounts of power as well. h: Enjoy.
Honestly, I'm not sure what I want to do with the car: whether I'm going to get rid of it when I graduate college, or keep it long term and modify it. I enjoy the Integra a lot, but its a slushbox and its an LS. Of course I dream about doing an LS-VTEC and a manual tranny swap, but its not the most sensible thing to do. Trading for a GS-R would probably be a better idea.
For now, I'll look into replacing the shocks, then if I decide to keep the car, I can always go more extreme.