PDAs or Public Displays of Affection

Earlier today my spouse came by my work on his way to work to say 'hey, love you, have a good evening, see you tomorrow sometime... yadda yadda'. We pretty much have the proverbial 'ships passing in the night' kind of relationship; he works the evening/over night shift and I work normally days some early evenings. So our time together, when we're both awake is very limited. Which I absolutely hate, it truly sucks and I wish it didn't have to be this way... but I digress.
So when he stopped by I came out from behind the counter (I work in our local mall in the customer service department/Smoke Shop) to give him a hug and a kiss. I mean, after all it's the only 3 minutes out of a 24 to 36 hour period I get to see him awake, for crying out loud! For me, my day was nearly over and it had been a slightly stressful and extremely busy one and I was just completely discombobulated, so I wrapped my arms around him and gave him a kiss. Not thinking of our location or who might be looking. I just needed a moment in his arms to rejuvenate me. The tone he used when he said my name and pretty much backed up from me held a lot more. I'm not sure if he was embarrassed or just didn't think that was appropriate since we were in public, I'm not certain (after all, I didn't have time to ask him) and that got me thinking.
What IS acceptable in public when displaying affection toward your spouse or loved one?

Working in a mall, I see people walk by holding hands all the time. I think nothing of it. I especially think it's adoarble when it's an elderly couple. So, to me, hand-holding is an acceptable display of affection. Personally, I like holding my honey's hand. Not only is it a declaration to the world that this is MY man, but it makes me feel all warm and fuzzy inside.
This I like.
Now kissing on the other hand, that's an iffy one. I see absolutely nothing wrong with a quick peck on the lips; as a 'bye honey' or a 'see you later' sort of thing. But if you're going to muckle* onto him/her and suck face - that, to me, is completely unacceptable.
I've seen it happen, and I'll admit to being guilty of muttering 'get a freakin' room already' under my breath.

* muckle: To latch onto, tear into, hold fast, grip, or grasp as an object or concept. (as defined by Urban Dictionary http://www.urbandictionary.com/define.php?term=Muckle )

By invasion of space I'm referring to those couples that like to affirm their 'couple status' by putting their hands in each others' back pockets. I've seen it many times also, and not just with teenagers. Although with teenagers, it's not exactly acceptable, but almost expected. It's a new frontier for them and they're testing their boundaries. Adults over 18 really should know better. Going to such lengths to claim your companion is sad and tasteless. I deem this inappropriate for public consumption.
This also goes for those couples who sit on benches, window ledges and the like and drape their legs over each other. Teenagers or not, this is improper and objectionable.

I won't even touch on the babying, pet names or smacking or grabbing your partner's ass. This, on principle alone, is completely, absolutely, categorically and without question unappealing and repugnant and should be something kept behind closed doors.

Every relationship you will witness or will be in yourself for that matter, will have some form of PDA. Nevertheless, it is my opinion that there are unwritten 'rules' that should be abided by.
If it makes you uncomfortable to observe or hear chances are you shouldn't behave that way either.

What do you think?