Well Tg cant help much on the safety features thing, what happens if you touch the f or r pedal? Sounds like what a well designed machine should do,, them seat switches on their own sound like a pain in the rear honestly and JD was on the stick if it only shuts the machine down if you are out of the seat AND try to move the machine,,, heck I might even leave something like that hooked up, sounds like an excellent idea.
The brush hog,,,, well I kinda think it's one of those your milage may vary type a things,,, I have used a 72" on my 5020 and it played with it in heavy weeds, but my heavy weeds may not be as heavy as your heavy weeds and I may think 4mph is flyin while you consider it crawlin. The only issue I had with a 72" cutter was the weight of the thing and the leverage it exerted on the tractor, I could lift the cutter and then the cutter would lift the front end, nothing some weights couldnt solve. 72" cutter on your machine,, unless it would be for maneuverability/gate issues I think would be a waste,,a 96 or 120,, now we're talkin.
The brush hog,,,, well I kinda think it's one of those your milage may vary type a things,,, I have used a 72" on my 5020 and it played with it in heavy weeds, but my heavy weeds may not be as heavy as your heavy weeds and I may think 4mph is flyin while you consider it crawlin. The only issue I had with a 72" cutter was the weight of the thing and the leverage it exerted on the tractor, I could lift the cutter and then the cutter would lift the front end, nothing some weights couldnt solve. 72" cutter on your machine,, unless it would be for maneuverability/gate issues I think would be a waste,,a 96 or 120,, now we're talkin.