When playing as Starkiller, you will usually have to find secret ways around, usually using the force. One of these techniques would be blasting or dismantling doors. Most commonly there will be tight, locked doors just waiting for you to blow them open. A regular blast won't open it quite, two or three will usually work, whereas one charged blast will open it enough for you to go through.
Second type of doors.
The second type of doors would be large, tight-shut doors, that are seriously huge. There are two ways to open them. One way would be to force push-repulse until it opens, but the faster, more secure way would be to pull the door with the force.