Welcome. My previous camper, a popup, required a sway bar. It was suicide to try to tow it w/o. It was heavier than the 'pod and should have had a WDH too, but I didn't (I used air bags in the rear springs of my TV).
I towed our 'pod for a year w/o either and it is the most comfortable trailer I've ever towed. However, a long trip home from the beach this summer convinced me that I should get some sway control, and since I was going that far I might as well get a WDH that included sway control. As comfortable as the ride was before, the WDH made it 1000 times more comfortable. So its really up to you - try to tow w/o sway or WDH then decide if you need either or both.
If you will always camp with hookups the battery is really only needed to power the emergency breakaway system. If you will boondock often, but if you mostly plan to camp on weekends then a 2nd battery is unnecessary. There are ways around getting a 2nd if you only do one week-long trip a year. If you boondock more than that, then a 2nd battery is a good idea.