This is actually already a column in the spreadsheet. You'll be able to see it if you download the unlocked version and change the background colour to white on all the cells. Or alternatively, you can look at the Skill Grades sheet which shows roughly what stat at the combine (or what skill grade) translates to what rating.
40 yard dash = speed.
Bench press = strength.
Vertical = jumping.
3 cone = agility.
Shuttle = acceleration.
Yeah I'd say so. A QB over 95 on the true value is worth moving heaven and earth to get hold of (they're likely to be the 83, 84, 85 OVR Superstars), but one between about 91 and 95 is still going to be a good player. He might be a 77, he might be an 83, but he's worth a top 5 pick for sure.