Macro alage, if it is what I think it is I have it in my tank. Wont do any harm but can grow quite big (easy to prune back though and good for nutrient export). Can't remember the name off the top of my head, begins with a H though (not a great help I know ).
Toadstool looks great, lighting you have should be fine for it and they like fairly good flow too. Also love the cleaner shrimp. Once I get my main tank setup again and everything moved back in I want to get a colony of these guys
It is halimeda, it's a macro algae that has a calcium skeleton so acts much like a coral, if it doesn't get enough light or nutrient it will bleach and go White.
Macro algae is a fantastic nitrite export do result