This is our third year with a Nature's head
and we have no intention of going back to a holding tank
. To answer your questions
1. Sure you can put paper in. It decomposes. Unlike a holding tank
there is nothing to clog up, you can put any solid in the composting bin.
2. The hole is big enough. If you are worried about it Nature's head recommends you put down a bin type coffee filter and aim for that. (See question 1 about paper).
3. We use it for two people, coastal cruising and a two week vacation
every year. I dump it the next spring. No sticking, no mess, definitely no smell. It looks and acts like dry dirt.
According to Natures Head it's good for about 60 "loads" when used full time. While I haven't tested this out yet if I had to empty it after recent use I would dump in some extra peat moss or other filler, mix it up and dump it into a trash bag or preferably over the side when offshore
. I don't think it would be as big a deal as pumping out the holding tank offshore
I don't think any of your questions are real issues. The two issues I have is that the pee bottle needs to be dumped fairly often which can be a hassle when you are spending time close to shore. And ours is mounted fore and aft which is a pain when we're well heeled over on a starboard tack. I wish the division between the liquid and solid path were a little higher.
That said I have had much less problems with it than with the holding tank systems on our last two boats. One holding tank overflow was enough for me. And the Natures head has never smelled as much as any of the offshore pump outs of the holding tank.