What are all these holes for?

So I just got my new RPM Intake and was going to install it and I have two questions. First, I am assume I need to remove the pens on the front and back of the block to get it to sit flat correct? Second, I noticed an extra hole in the front of the intake. There is the temp sensor, hose hole, thrermostat housing, and throttle spring mount hole, but then there is an extra one at the front. Is this for an electric fan and I should just plug it or am I missing something. Then there is another extra hole back in the back left. I can't think of anything to go in this hole so should i plug it too? I need help asap because I am hoping to have it all finished tomorow.