Nice write up.
Strict form is something we must always be mindful of, no matter what the weight but especially when lifting heavy.
The bench press is one of those lifts every novice wants to see how much they max out on and it's also the place where many suffer shoulder injuries without even realising.
The correct position of your elbows, about 45deg inwards, during the eccentric and concentric parts of the lift plays a vital role in getting maximum power and drive from the chest and arms. Doing so also takes a huge load off the rotor cuff and the intricate supporting muscles that surround it (and often the muscles you've damaged inadvertently through poor bench press form) As a guide, if the bar is coming down to just under your chest, you're on the money. If the bar is coming down on your upper chest/neck area, you need to make some technique changes, fast.
Leg position is often overlooked as not important, when in fact, it is one of the most important parts to get right if you want to get the most out of the exercise - as a few have already mentioned after playing with leg position, it made noticeable improvements. Where you should have your legs has already been covered well by the OP but I will add this; it is highly recommended to spend some time playing with leg/feet position, because being able to get maximum amount of drive from your feet, up through your legs, has a compound effect through your whole bench press setup - right up to how much you can or cant lift. When you find the right foot position, and you have the rest of the setup squared away, you will know because what you were previously struggling with just became so much easier.
And if you bench press with your feet off the floor / knees to your chest, not only are you putting yourself at great risk of injury, you aren't getting anywhere near the benefit that this great exercise can bring using the correct technique.