I don't think you can evaluate a GM's moves unless you put them in a situational context. These moves don't happen is a vacuum.
Vargas for Morales: Both players were going to be free agents at the end of 2013 and the Angels were not going to re-sign Morales with Pujols, Trumbo, and a host of younger, cheaper options. Angels needed SP and Seattle needed offense - deal made sense for both parties. Morales is essentially a one-trick pony - a DH playing 1B with zero speed and late-order pop on a good offense. RIght now his numbers are .280/.337/.800 which is good but not spectactuar for a 1B. Vargas averaged 200 innings and 3.80 ERA 1.25 WHIP the prior three seasons and averaged looked to be a solid back-end starter. He was busy matching the numbers from the past three season when he developed a blood clot, which I'm sure everyone here predicted would happen (haha). This was a good trade.
Hanson for Walden: WIth Santana, Greinke, and Haren not coming back, Dipoto essentially had three rotational spots to fill. Vargas filled one of them using a surplus of IB at his disposal. Hanson for Walden was essentially a swap of projects by the two teams. Walden, armed with a fastball that could touch triple digits, struggled with location (4.4 BB/9) and mechanics, was poor in high leverage situations, and dealt with bicep issues. Hanson was a top pitching prospect that found initial success but struggled with injuries but, up until last season, averaged a 1.18 WHIP and a .225 BAA. Project for a project...it wasn't a bad nor expensive gamble. Who could have predicted his brother's death? How do account for that as a possiblity? I'm not busting him for this one.
Dane De La Rosa: He found this guy totally off the radar and he has a delievered with a 1.11 WHIP, .224 BAA and 40 K's and only 13 BB in 43.1 IN.
Sean Burnett: He's averaged 60 appearances since 2008 with a 1.20 WHIP and a has been especially tough on lefties (.227 .293 OBP .567 OPS againt). Unless you can read the future, don't see how this would be considered a bad signing.
Ryan Madsen: A $3.5 mil gamble on a potentially quality arm...how is this a big deal?
J.B. Shuck: Despite his defensive misadventaures, has a been a solid fill-in aquired for cheap.
Ernesto Frieri: Despite a couple of meltdowns, the guy has converted 22/24 and is sporting a 1.16 WHIP .178 BAA with 61 K's in 40.2 IN...and he got him for this generations Alfred Almezaga.
Chris Ianetta: At the time, when they traded for him, Chatwood was giving up a BB for every two innings he pitched and it will take more than 70 innings of 1.29 WHIP .260 BAA to make me break out the torches on this deal.
Not signing Torii Hunter: He was 37 coming off one his best seasons hitting in front of a HOFer and he had the great fortune of finding a similar scenario in DET. He also said he'd here for a discount...until the first two year deal came his way. The only mistake the Angels made was signing Hamilton instead.
The fact is there is logic behind these deals, sound logic, and for one reason or another they haven't worked out. The only obvious and glaring mistake is the Blanton signing, which cannot be defended.