Hi, and thank you, Sarah! I don't keep an active species list for my flora or fauna. It is always evolving and I don't have much time to keep track of everything in a list form. If someone is interested in something they see in a picture, I'll ID it for them. It's good enough. I'm also busy with other projects, and time is not very plentiful right now.
Regarding the Flamingo: I don't really know how to answer that question. If you have a high tech set up with all of the bells and whistles, keep a nice few-inch barrier around it where other heavy-root feeders don't come into, and keep the leaves from getting a lot of detritus build up on them, then it doesn't seem too finicky. However, it does seem to take some time to get established, and I won't feel very comfortable recommending it for a novice to try until I get get a few generations of daughter plants. It was suggested by a buddy of mine that the mutation may not be very stable, so it should prove to be interesting to see what happens over time with this crypt.
Hey Ua Hua! How've you been? Yes, the Selaginella species can survive very nicely completely submersed. It will climb the mosses and branches without any problem, and grow emmersed as well, but it won't climb any more than an inch out of the water where it still saturated by water.
I do like the true sag as well. It's very easy to keep and control, and as I have much less time nowadays to fuss with the tank, it is a perfect choice for my tank as well.