Ahh, that was nice. I often toy with the idea of converting my 110 to a 130 someday.
I see where you are coming from, and to a certain extent I agree. My own experience has suggested when it comes to powertrain, stick to original where ever possible. Makes repairs and parts so much easier than a frankenstein of hard to locally source bits and pieces that a standard technician can't look up in a factory book. I also think however that when a vehicle gets you as close as you want to a platform, but there are a few shortcomings, those are appropriate things to "modify". Example is upgrading to HD axles on Rovers with weaker stock axles.
And with suspension, the philosophy of "only what is needed" I think is a good one. I've also learned on previous vehicle that when it comes to suspension upgrades, not to just thow in new coils or leafs and quit there. The suspension is a complex interaction of components, and the only way to get a real sustainable improvement is to make sure the entire suspension system is corrected for the lift to account for things like driveline angle and castor.
I think however that the most common error in modification judgement is driven by appearance as the driving force. 'Cause it "looks cool" is not a practical reason to modify so as to add weight or change engineering dynamics. I'm a true believer in "Function Before Form". I need a good rational for every change I make to my 110 to fill an actual need. Even my "Expo" sticker has a purpose! And if I later determine that a mod actually was not needed or used, then off it comes. No reason to add unjustified weight, take up space, or add complexity.
I also have come to learn that when I am considering a mod, I need to take a good long time to consider it before implementing; almost like a probationary review period. In the past, I have often had the light bulb hit on a mod, then next day I go out and purchase, drill, mount, only to find that the mod interferred dramatically with another future mod, a function of the vehicle I had not considered (e.g. rear seat folding, accelarated wear on critical component due to rubbing from road vibration, or access to something later for maintenance/repair) or lastly, impracticality of use (e.g. mounting a heat exchanger connection point to the front of the vehicle then later discovering you really want it in the rear of the vehicle).
In short, when it comes to mods, "bling" is the anti-christ of the overlander.