From some of the road test videos I've seen, the lane keep assist didn't always keep the vehicle precisely centered in the lanes. If that's anyone's main reason for skipping the SE trim, I'd reconsider.
It varies greatly. It could be free (included for 2 years from purchase on Electrify America chargers) or it could be charged by the minute or energy distributed to the vehicle. Even in most cases it should be cheaper than the equivalent gas vehicle. If you charge at home, it will be roughly equivalent to the cost per KW your home energy provider charges.
Are the H-Tex seats that much better than the cloth? I've seen the cloth in person and it felt reasonably durable albeit perhaps a little thin. Do the side mirrors fold if you lock the car with the keyfob or do you have to push the button while inside?
I have not felt the cloth in person (However I will be shortly given we have an SE in stock now) but they are two totally different materials. Some people like one vs the other for various reasons. The power folding mirrors do automatically fold upon locking or you can set them not to fold.