ok so do i need to talk to anyone at the ncr or do i just do what the boomers ask of me and then talk to them about it.
Once you do a series of quests for the Boomers (most of which are quite fun) then they will pledge to help you when the time comes. You can tell all the other people whatever you want about whether the Boomers will help them or not up until the last part of the MQ. Then you tell the Boomers what you want blown up, and they do that for you.
Or, as stated above, you can ignore them. However their help in the final battle is a good thing.
Now, if you want to do things your way, then work with Yes Man and you can do what you want at the end, even while telling House, Caesar, and the NCR that you will do things for them as you go along.