The grassy looking ones, may be valisneria of some kind, or possibly one of the narrow leaf sword plants.. it's bit hard for me to see details. The broader leaved ones, I think, are also some kind of Anubias. There are several types, and telling them apart is not always easy. Slow growers, and yes, should be tied to rock or wood. String will rot eventually, best to use poly thread or fish line.
The one in the middle of the last pic looks like it might be a crypt of some kind.