Right now I have 2.5" IC piping. Is the same concept w/ exhaust piping going to be the same w/ IC piping? Basically would it be better you run 2" or 2.5" piping?

I'm not really sure but puttin 2.5" piping on my car gave me BOV flutter. I guess it's good if you are running a lot of boost and I'm not hehe...

I say 2.5" i/c piping with a stage iv; or, you could do a 2.25" i/c piping going from the turbo to the i/c inlet, then a 2.50" i/c piping going to the throttle body. At least, this is what I'll be doing when I redo my i/c pipings setup (when I can find some money;)

With stage 4, i would go 2.5 piping.

hahaha boy 2.5" piping is really overkill for me

I with ya on that. I used 2 inch mandrel bent for all intercooler piping. I even left the stock endtank piping on the starion. This is working great for my application. I really think piping size depends on boost pressure and intercooler efficiency. If I was running 20 psi and had a huge front mount(spearco or griffin core), then I would be restricted by 2 inch piping. 2.25 is plenty big at this point. If you have a sheetmetal intake and a 3 inch throttle body, you need 2.5 inch piping.

and what does the star kit come with?

I have 2" going from the turbo to the FMIC then 2.25 going from the FMIC to the throttle body. I am pretty sure that is what the HRC staged 2 kit comes with.