Sand alone has nothing benificial. You would have to use root tabs.
But if you put sand on top of a soil based MTS, then it will be good for plants. but most of the time it doesnt last that long
It all depends on what plants you want to have.
I wouldn't say it depends on plants. I would say it depends on your setup. A low tech tank would last for quite a while. The demand for nutrients would be low. Once you add co2, higher lighting and dosing fertz, this is what depletes the soil.