Player for player, I do not like the trade above, but like you said, you just want to improve picks and are willing to use non-keepers to do so. You have accomplished your goal, and I applaud you for that. If the other GM wants to/needs to use ROR, Skinner, or Schultz as a keeper, then I wouldn't think that he is much competition for you, so don't hesitate to make sure that you at least make that much happen.
Onto Hall vs Getzlaf. My gut says Hall, and it says that this is a very easy decision to make. You save $2.25 M in cap space, and you're getting a two-time, top 10 scorer, who is just 23 years old, and about to have Connor McDavid as a running mate for what is assumed to be a very, very long time. Of course, the big issue is his injury history.
I posted somewhere else that Hall has a career 0.97 PPG, and this was before the arrival/emergence of many of the offensive weapons who they have now. I think that he should easily score at a 1.1 PPG (90 points over 82 games), and without too much of a stretch, bump that up to a 1.15 - 1.22 PPG pace (95 - 100 points over 82 games) with McDavid by his side in some form or another (ES and/or PP).
Now, you need to factor in his injury history and determine how many games you need out of him to match Getzlaf's projected point totals. Let's put Getzlaf at 80 points. At 1.15 PPG, Hall would need to play 70 games to get there. That would be the second highest games played in one season of his career. Can he do it? I think that, going forward, he will reign in some of his "enthusiasm" for physical plays and learn to how to better protect himself, and therefore stay in the lineup on a more consistent basis.
To put the nail in the coffin on this, let's do a couple simple calculations. Let's say Hall is somewhat injury riddled and therefore puts up 70 points. That would be equivalent to 11.67 points per $1 M. If Getzlaf hits his PPG potential and puts up 80 points, that is equivalent to 9.69 points per $1 M. Even if he's hurt, Hall provides better value and allows you to spend over $2 M elsewhere on upgrading another player or players.
Easy pick is Taylor Hall for me.