1. For grass like appearance, Dwarf hairgrass; Elocharis acicularis or Brazilian Micro Sword; Lilaeopsis brasiliensis would be good choices to use
2. Java moss, Christmas moss, Flame moss, Mini Pellia, Fissidens fontanus, or any other mosses can be used with drift wood, just be aware that some mosses will grow quite large and bushy
3. Anubias Barteri Nana and Nana petite makes great middle ground plant, I also like to use Green Cryptocoryne; Cryptocoryne wendtii 'Green'
4. I'm currently growing Moneywort; Bacopa Monnieri however it's a slow grower. There's a wide variety that I'm not too familiar with, nor do I have access to so I can't really help out here