Honda is not going to warranty anything that lift touched anyway. You kind of forgo Honda and do it at your own risk. I am not an expert to say what the axle relocation kit will impact other than the angle of the axle? You are already changing an axle angle by lifting by more than 1 inch. One might argue that if you go 1 inch to the front it is not that big of a deal since you already went down 2 inches with the lift.I agree with @Tamak44 as I watched the install video on YouTube and it’s definitely quite the job to install, and there were steps where it looked like it would be easy for someone not experienced with Honda to yank on the axle too much and break something. Actually, now that I say that, I think I remember someone having that issue on a lift install, might have been on the Ridgeline forums, and the shop had to pay for a new axle boot or something. In any case, it could be done, but I’d want to show the shop all the instructions before pulling the trigger, to see what they think, and gauge their confidence.
As for the wheel well cutting, it depends on how large a tire you go. JonDZ cut his wheel wells, but that package seems to include the axle relocation arms which move the tire forward enough to clear some larger tires, so the wheel well cutting might not be needed, depending on how large you went. It does look a little odd though IMO, with the front wheels being pushed slightly forward and off center from the wheel well, and I’d venture to guess if anything goes wrong with that front-end, Honda will blame that relocation piece since that’s probably a more rare and significant change than even the lift. I’d lean toward cutting the wheel well myself as JonDZ did.