There are few arrival requirements for Operator such as applying for and getting approval of VGP, COFR etc. These requirements are not only for Houston but all US ports. For Masters arrival formalities include sending the timely ENOA/D and reporting of ballast water exchange.

If you have followed all the arrival formalities, the departure formalities are not much of hustle at Houston or any other US ports.

Master need to send the Departure ENOA if Houston is the last US port of the ship.

For unberthing from Houston port, there is a minimum tugs requirement which is calculated based upon Ship's engine size and size of the bow thruster if Fitted.

So if bow thruster is not working, master need to inform the port through agent about it. 

I am not aware of any other special requirement for port of Houston.