I've got a 5.5g planted and have grown lots of plants in there. Most I've moved out once they were too big.
Right now I've got anacharis, Hygrophila Difformis, Java fern, Java moss, and a mondo grass thingy. The anacharis and Hygrophila need trimmed often, so you may not want that. The Java fern is fine, Java moss is a little unruly, and the mondo grass is just the right size, might be a good option for your number 5 plant if you don't mind that it is pretty much a rosette.
You could consider Pennywort for your number 4 plant, but again, you would likely have to trim it often. I'm partial to spiral Vals where you have your Number 1 plant, but they would be bent over at the surface and would likely go diagonal at some point.
My favorite plant that I had in my 5.5 and would highly suggest was an E. Parviflorus. It looked great in there and was a perfect as a focal point. For some reason that currently escapes me, I decided to move it to another tank where it now lives and is thriving.
Good luck!