Rock Raiders can be named by simply pressing [ENTER] after you have selected a single Rock Raider. The game will then pause to allow you to type your own custom name in for the Rock Raider. The Rock Raider's custom name will appear above his head afterwards.
Land erosion by lava can be slowed down by building a power path on the land. However, eventually the power path will be destroyed and the lava will start eroding the land again. You will then need to repair the erosion and build a new power path there if you want to slow down the lava again.