Wow — tough, tough puzzle today! Tough cluing, awesome long entries, misdirection, sparkly fill — welcome back, late-week LAT!
I can't say that I knew ADAM BALDWIN's name off the top of my head (or at all), even though I watched the first couple seasons of "Chuck" religiously (1A: Co-star of TV's "Chuck"). I'm guessing he's the guy who plays Captain Awesome. Let me see … Nope. He's Casey, the crazy NSA agent. Funny, funny guy. I would have had a better chance guessing if I remembered anything about MY BODYGUARD (56A: 1980 film debut for 1-Across).
Of course, I wouldn't be doing my job if I didn't mention DADOED and RACKER (2D: Grooved, in carpentry / 42D: Eightball loser, often). They are, to me, the ugliest things in the grid. It's interesting that they're symmetrical though. Makes me think it was planned that way. And besides, I think I'm more disgusted with the clue for NO SALT (11D: Margarita option). What's the point of a margarita with NO SALT?!
As for the 15s, I love BORDERLINE CASES (14A: Situations that aren't clear-cut), even though it's clued straightforwardly. I don't think I'm familiar with ROCK 'N' ROLL IS KING (52A: 1983 ELO hit with the lyric "She loves that drivin' beat"), but wouldn't be surprised if I find it on YouTube and go "Oh that song!" (I admit I tried Rock 'N' Roll Is Dead at first.) …. Nope. Just found it on YouTube and it's a Chuck Berry rip-off that I don't recall ever hearing before.
- 12A: One might raise the roof (CRANE OPERATOR). Great clue.
- 16A: State with a five-sided flag (OHIO). I did not know that.
- 27A: Kind of well (ARTESIAN). No idea what this clue was going for. Health? Steak?
- 36A: Exude an air of disinterest (BLOW COLD). I'm one of those people who recognizes a distinction between uninterest and disinterest. I'm not sure this clue is accurate.
- 4D: Hired gun, briefly (MERC). Short for mercenary.
- 5D: Official ties of New Mexico (BOLOS). I had no idea New Mexico had an official tie. I did learn recently that Wisconsin has a state microbe though.
- 14D: Tony-winning star of "Where's Charley?" (1948) (BOLGER). When I finally had enough crosses in place, I realized this was probably Ray BOLGER, more famous for playing the Scarecrow in "The Wizard of Oz."
- 39D: Triage MD (ER DOC). With the D from ADDS in place (48A: Goes on to say), I tried medic first. Tricky!
Everything Else — 17A: Raccoon kin (COATI); 18A: Multipurpose lyrics (LA LA); 19A: Story (LEVEL); 21A: Cat lead-in (SNO-); 22A: Plush, in a way (PILED); 23A: Top quality (GRADE A); 25A: Oregon Trail river (PLATTE); 26A: It's often smoked in Sweden (EEL); 31A: Some rtes. (RDS.); 32A: Luminescent critter (FIREFLY); 33A: Org. that infiltrated Germany in the '40s (OSS); 37A: Balderdash (PAP); 38A: For only a select few (SECRET); 41A: Very much (SORELY); 43A: Aquiline nose, e.g. (TRAIT); 44A: Area between N. and S. Korea (DMZ); 47A: Capital east of Dhaka (HANOI); 49A: One of the fire signs (ARIES); 51A: "Let's go!" ("C'MON!"); 55A: They may be spotted at pet stores (CALICO KITTENS); 1D: Airport board heading (ARRIVALS); 3D: Hydrocarbon suffix (-ANE); 6D: Like bees (APIAN); 7D: Tempo marking (LENTO); 8D: Bavarian trio (DREI); 9D: Mil. branch from 1943 to 1978 (WAC); 10D: Restaurant guide category (ITALIAN); 12D: Stuck (COHERED); 13D: Got a new tenant for (RELET); 15D: 1986 Best New Artist Grammy winner (SADE); 20D: Certain handout (LEAFLET); 22D: Toy in resealable cans (PLAYDOH); 24D: "__ is the language of the unheard": M.L. King Jr. (A RIOT); 25D: Dispensary stock (PILLS); 28D: Credit checker Experian, formerly (TRW); 29D: Continental trade org. (EEC); 30D: Virgin America hub: Abbr. (SFO); 33D: Negotiating asset (OPEN MIND); 34D: Watering holes (SALOONS); 35D: Bond activity? (SPYING); 36D: How a cool wind blows (BRISKLY); 38D: Macy's logo (STAR); 40D: High-tech engineering acronym (CADCAM); 44D: Title name in an unfinished Dickens work (DROOD); 45D: Whitish (MILKY); 46D: Chameleon-like Woody Allen character (ZELIG); 49D: String music direction (ARCO); 50D: In __: as found (SITU); 53D: Tip of a pen (NIB); 54D: RR depot (STA.).