MS-65 [not full steps...they seem to be worn]...the luster looks strong, but I see a few bigger hits/gouges (like on the reverse between "five" and "cents" and to the left of the "o" in "OF AMERICA...")
You missed one, the Mark under the U. For sure, the ones above the Monticello are the only ones that are bag marks, but the others are definitely still worthy in considering the grade.
The quality of coins produced in 1955 was atrocious. This is one of the best I have ever seen. I'm going to say MS66, simply because it is better than my MS66.
No, that is actually a strong strike for that year. Crack that puppy and send it to NGC. If the luster is all there, which it looks like it is from the first set of photos, it goes MS65 all day, with a good chance at MS66. Like I said, it is better than my MS66.
I have several at MS66, they are common and have a stronger strike. Look at the detail in the hair and the lack of steps.
It is definitely a later die state in hand. I have been trying to get pics of the D/S. It's a hard one to capture.