Excellent stuff, Spec.  
In short:  Don't bet the mortgage on Rugi being great.  The good news is it was a (relatively) free roll of the dice.  If he craps out we haven't lost anything we don't now have and couldn't afford to lose.  
As I've said, I have little doubt that with 40 games of Tacoma under his belt (in RF) that Kivlehan wouldn't just step in and be a real contributor. And Romero may find his MLB mash vs. lefties this spring.  But those guys don't play CF (although I wouldn't mind seeing Kivlehan play there in Tacoma, too---The guy was a college safety, for goodness sakes...he certianly has the athletic chops to chase down fly balls in the center of the field) and we needed an extra one of those.  Clearly Rugi wasn't on our radar for long.  Being shut out of the RH bats he really wanted, Z jumped at a guy with some success with the bat.......nebulous as it may be. 
We've another move to make, for sure.  I wouldn't be surprised if it was a 1-yr 1B/DH type bat, and we give Cruz 120 games in RF.  Or Rasmus.  Deej is a 1B/DH type, by the way.  
The more I've thought about it I think we blew a great opportunity with the Nationals.  I wonder if we could have got Espinosa AND Souza for some kind of package that included Ackley and Taylor (and I like Taylor).  But that is water under the bridge.  The bet there is that Souza in CF is a better long-term asset than Taylor at SS.  
The next move we make will indicate just how much Z thinks we can get contribution from the young guys we have right now.
But Rugi MAY have made us somewhat better....in the 45 games (or so) that we face lefties.  If he hits 12 homers this year, and 7-8 are vs. lefties, then he's been a decent addition.  More is real gravey.
 
 
 

Not to pile on, but Ruggiano's contact issues got worse in 2014, he had a 2nd half swoon, and a high BABIP in low PAs that masked the down season. All signs of aging. I think he could be a useful 4th OF, but its equally likely that he flames out. Not a bad gamble, but we should be willing to swap him out quickly if he doesn't show up early on.

And he won't know any of the pitchers (until we get to the WS that is lol).

He's entering his age 26 season...seven years in the minors that didn't give him a sniff of the majors until an eye-popping season last year in AAA--built on a ridiculous .400 BABIP.
Steamer says .737 OPS next year; not terrible, but maybe not worthy of the salivating? 26 plate appearances so far in the bigs. 26.