Re: Our first RV is a B, suggestions for "things to have?"
Certainly, working with a sewage tank would not be fun. And improper care of a tank will increase the chances of it needing service. But there is more to tank care than 'chemicals' and 'RV toilet paper'.
Chemicals are not magic. They are aides, only. Using them does not guarantee a pristine tank, and not using them every time does not guarantee a disaster. Many of the tank additives are 'enzyme' based, which help the bacteria in the tank dissolve the solids (and paper) at a faster rate. Some are cleansers, which make the water 'wetter' to help clean the surfaces in the tank. Most tank chemicals also help reduce oder and lubricate the seals of the valves. Generally I would recommend using them; particularly for occasional users. Many full timers claim they don't use chemicals, just lots of water, and don't have any problems. Are they hastening the demise of their tanks? Maybe, or maybe the excess water and continuous usage with good dumping and cleaning techniques are just as effective as the chemicals.
As for RV Toilet paper, there is nothing special about it. It is chosen to dissolve quickly in water. In many cases, this is by having it be a flimsy 1 ply. Any toilet paper which dissolves at the same rate as the 'RV' paper should be equally good for RV use. Scot single ply and the stuff you get at CostCo are touted as being equivalently RV friendly, and are probably 1/2 to 1/10th the cost of the official RV stuff. If you like, you can experiment to find a brand or brands which are equivalent at dissoliving as RV paper, and start out, at least, with a stock of the cheaper stuff. If you run out on the road and can't find your normal brand, the RV brands would be safer than any untested brand.
I think that proper dumping and cleaning techniques will have at least as much impact on tank life as the chemicals used. And will minimize the problems of toilet paper fouling or clogging by most reasonably non-durable brands.