like in the youtube video i saw fix emplacements, will we have the ability to build and repair such objects, and also will we beable to put in missle turrents and laser turrents like they are in the original mechwarrior? And will there be a engineer class to maintain all of this? If this has been brought up already then i do apologize

The initial plan was to have turrents buildable and or deployable, but at this time in the design they are simply fixed emplacments.  They will remain that way until we have the time to figure out how the turrets in crysis are set up and if they could be deployed or not.  Its something on the backburner at the moment (too busy doing everything else! )