what type of actions would void the warranties of my 98 Accord EX?

What warranties are you talking about? Most likely any aftermarket (non-genuine honda parts) will void that part and or parts directly related to it. Or maybe I misread your post and you are thinking of tweaking, removing or adding something so please write back and explain.

ive asked Honda the same question. what they said was that they know about how a lot of people install intake, exhaust, altezzas and so on, then come to get service and put back the factory parts. they said that there is really nothing they can do if when u come in u have ur factory parts in. But if u come in to get service and have aftermartket parts in ur car (ex.such as altezzas) and it effects the electrical wiring in ur car the it will void coverage for ur electrical system.<br>hope that helps a little bit.