Profitability of mining is not always constant or fixed, this is changing drastically either dipping below or going high, crypto profitability online calculators is a good reference to see if your GPU's would be profitable or not at least for the day.

http://whattomine.com/coins

If you are renting and have a low electric cost it is your advantage, just ensure your lessor approved it


This is actually depends on your budget plans, locations as you will need to prepare your electrical, ventilation, etc.  especially if you would create a farm