Im stuck at a current bench press weight now for a while and I think its my form that is the limiting factor...

I focus on getting "tight" under the bench, pressing my traps together and planting my feet hard on the ground, tighten my abs and glutes and then lift off.
#1: Ive read some that your to "rest" on your traps with a more extreme arch to your back then what Ive got... Once again, my focus has been on staying tight, not arching. Any truth to the "arch"? And does foot placement come into it? Ive read some as well that they "push" off with their feet and keep them tight under them.
#2: I think elbow flair is an issue as well. How tucked do they need to be? Ive been catching my elbows getting out there on the heavy lifts and have been incorporating more close-grip bench presses and pressing to the lower abs/chest instead of upper chest to reduce the flair.

Any advice people? Help a brother out.