I had no idea about warranty being voided although I have had no warranty work on either 30W or the current 30T on anything involved with suspension. From what I have read modifications are common. You are new to the motorhome so it will take awhile to get used to driving it. Remember it is a kite. I would first do the cheap handling fix and also adjust tire inflation. I would also then add a good steering stabilizer. See how that goes and work from there. Cheapest things first and build. I do think a good rear trac bar will be important as well. Keep us posted on how it works and what you learn.
