[rvcycleguy]

First question first... 2 batteries? Both 12v? If so, then leave one at home. If they are 6v, then they are tied together and need it for 12v.

Regarding propane tank, possibly leave it at home but some systems with 2 hoses and the quick changeover lever may require a tank to be fitted to the hose. Meaning no tank may allow propane to leak from the hand twist threaded fitting.

With your math, a TM that weighs 2900lbs, and the 10-15% tongue weight suggests you have 300 to 450lbs of tongue weight. That sticker should indicate dry weight. Does not include propane, battery, water, awing, etc.

Any weight you remove will ease the tongue weight. From the info you provide, I don't see any issue with stability either way, as long as the WDH is set properly. I'd check your vehicles gross combined weight ratio. Which is what the tow vehicle can accommodate for passengers, gear, plus TM and gear, total.