I can't say I agree with all of the "worst mods" being thrown out there but I will object to internal fill. I could care less about how "Cool" it may look without external fill.
I personally think pulling the hood off mid ride and post ride is very important. Gives me a minute or two to look the ski over and see if anything is out of place, loose, almost broken, or already broken. Call it preemptive maintenance or whatever you want but it really helps me keep the ski reliable. I always pulled the hood off anyway when filling up so I could see how much gas goes in. Overfilling and pouring gas all over your fresh paint job or into the water was never fun for me either.
Just my opinion...