My lockout sucks in my Shirt. I seem to get stuck about 8in or so off the chest and have a crazy time locking out weights.
I've been doing Floor Presses and reverse Bands. Anything else help out on lockouts?
I have been watching a lot of your practice in the gear. Your technique needs major work. Porky pointed out some issues with the squat above.
As for the bench and missing the lockout. Your problem isn't triceps. It's technique - your set up.
Look at a still image of you after unracking the bar. Your chest is flat and lower back is arched. Your arch should be in the thoracic spine.
Essentially work on thoracic extension, focus on chest up as you lower and press the bar. By this I mean think about having your sternum meet the bar halfway down. This will also force you to keep your shoulders mashed into the pad.
Once you nail that the lockout with go off without a hitch until you start getting into high 4's. But really by then the triceps will adapt on their own as you go up.