I was born and raised in NJ and spent twenty years shooting there before moving to America for the first time by way of Texas less than a year ago.
There are multitudinous questions here! Is your 'office' your own building with no other tenant or occupant? Or perhaps a leased unit in a multiple company building? Do you own the building/space or rent it? Are you near a school? Do you have a safe there?
As far as traveling, you must transport the arms and ammunition separate, both in 'secured' containers. Gun in trunk, ammo in passenger cabin or vice versa. As to keeping it in your hotel room; stored? loaded on the bedside table?
There are many, many ways to run afoul of law enforcement in NJ w/r/t firearms. Did you know that carrying a semi-automatic pistol magazine with even one round of ammunition in it, even with no gun that magazine might fit within a mile, is considered a concealed weapons offense in NJ? Did you know that if you go from your home, with weapons secured as specified by state law, to the bank, the dry cleaner, the range, then out for a burger and you get stopped for any reason by the police and they decide you've been joyriding with guns you could be in big trouble? One must go from home to range and back, no exceptions.
Don't think for a moment that using a firearm to defend yourself in NJ will not result in loss of the arm, thousands in fines, possible jail time, etc. Get yourself the name of a good gun rights attorney and pay for a consultation if you must, ask at the local gun club, study the codes online via NJSP, etc.
Good luck.