there is a lot of good information regarding a gardening method called lasagna gardening. What it calls for is putting down 4-5 layers of newspaper and then piling up 4-12" of mulch/compostable materials. Then, you plant directly into the loose material. You don't have to wait for it compost down.

I expanded my veggie garden this spring using the method and it seems to work fine. The newsprint is permiable and I don't have water sitting around, to answer one of your questions. I would just be careful to not put mulch right up against the plant but it sounds like you didn't.

There was one spot where weeds had poked thru so I put more newspaper down and then dumped a load of grass clippings on it 6" deep. I think that will do the job on the grass/weeds. And, in a few months, I'll turn it over and plant it.

good luck.

Water percolates through newspaper. That's why people use it. You don't need to leave a gap to let water in. You should leave a gap, to let air at the crown. 2" should be fine.