I bury my micro sword completely so it wont pop up!! It comes up through quickly and then spreads rapidly. You will want high iron substrate for them to grow fast. I get about two new plants a day right now.
Yes i bury the plant completely..might see a small leaf sticking up as it settles. The plant has enough stores to get a leaf out to get light after that. My substrate is not that deep. Id say about 2-3" in the front where they are. roots don't usually go down in an aquarium they spread horizontally. The closer to the water the warmer it is for the roots.
Although if I could go deeper I would.
I put Microsword in a 3 gallon Eclipse with Florite and it covered the tank so I am pretty sure an Eclipse will work. It still might be slow. I started having an Algae problem so I had to cut back on the number of hours I kept the light on. THis definitely slowed things down. Also after a while the Florite gets exhausted which also slows growth.