A few comments.
1) On the subject of using another first rounder on a left guard, I believe that's a viable option and not a waste of a pick. We're talking about a player that will play every snap on offense. Just because we already have four talented starters on the line already doesn't mean adding a fifth won't be an improvement. It only takes one bad player getting beat for your QB to get sacked after all; just look at the Atlanta game.
2) Not a fan of Ridley. I know he's amongst the best route runners in this class (definitely better than Moore is), but I think he's a bad contested ball catcher, he doesn't break tackles, and I question his blocking. Combine that with his age and poor combine numbers (my opinion, based on his weight), I'm just not interested in him.
3) At this point, D.J. Moore is my #1 receiver with an early 2nd round grade. However, considering my board, there are only a few slightly unrealistic options I'd take ahead of him, so I'm very comfortable taking him at #19; knowing that even trading back would risk losing him at this point.
4) While a great combine performance doesn't improve my grading of a prospect, in Moore's case it makes him much more desirable for what I want to add at wide receiver. Aside from simply having an overall higher athletic ceiling, Dez Bryant, Terrance Williams, Cole Beasley, Ryan Switzer, and Noah Brown all run slower than 4.50. Before the combine started, D.J. Moore was considered a risk to run a 4.60 and I was worried he wouldn't bring anything new to our depth chart. Instead he a ran a 4.42; showing he can be a speed threat while still providing legitimate receiving ability.