Now, I will TRY to answer your question(s), which are pretty broad.
I open carry for mainly two reasons; self defense, and I don't have a CCW as of yet. There is a lot of discussion among all carriers both types, concealed and open. Here is the dilemma I find myself in.
1. While OC may deter potential attacks, which cannot be certainly known, just speculated and assumed (unless there was a great amount of evidence such as them pulling a weapon, seeing a gun on you and running without you even drawing). It may also make you the first target. In any situation, open or concealed, once you draw your gun, you are making yourself the target of the bad guys fire, especially in a store scenario. That goes for both open and concealed. However, a lot of robberies in stores happen once the bad guy approaches the counter for instance. Say he's standing behind you with his buddy. He sees a chance to go ahead and get rid of the threat, and shoots you before you even realize what is going on.
Look at it this way, a criminal is a two-legged, slightly more evolved predator than what you see on the Nature channel, but a predator nonetheless. Predators have a great predisposition towards targeting the weak, old, lame, and alone ("soft" targets). They seek a favorable benefit:cost ratio (cost=risk of harm or death, in our example). If you want a cite for criminals being deterred by KNOWING or perceiving someone (potential victim) as armed, take this video showing the opinions of convicted criminals on the matter:
http://www.youtube.com/watch?v=xVK1xQoxhPI
Skip to 5:08 for the relevant part*(sorry for not embedding the video, but I am on my iPad and typing this up between classes. Maybe someone can do so?).
To me, it seems that a conceal carried fire arm doesn't make you the 'target' as quickly as an open carried fire arm does in any situation unless the bad guy knows you are concealing. What do you guys think of this? Remember, I open carry, and I love it. It's comfortable too, and I too have speculated on certain peoples intent. Such as eve last night when a car of 4 men pulled up behind me while I pumped gas, saw my gun, and sped off. I don't assume that I was going to be a potential target, as I still utilize a military style medium fade haircut, and wear nice clothing. As well all know as open carries, the first thought of most people is "He is a cop!", so it could be that a lot of these people may be in possession of drugs or something as simple as expired tags and they suspect a warrant.
This goes back to LOOKING like a hard/soft target. Even the ILLUSION of a reasonable defense will usually deter the criminal, who prefers a soft target to maintain a good benefit:cost ratio. Going back to the nature analogy, predators tend to skip over prey that just MIMICS a well-defended organism.
As a side note, make sure you don't let people believe you are a cop, as that defeats the mission of OCDO, which is to normalize OC of civilians, and not the "chosen ones" (LEOs and other government employees). Obviously clarifying this applies only to people that don't set off your "spidey sense".
2. On the other hand, what an OC'd firearm can do is keep you from being a potential victim, but giving the illusion that you are not armed. People assuming you are a cop is a good thing. Tricking someone into engaging you while you are armed almost forces you to act, which no one actually wants to do if it can be avoided. To me, conceal carry has the element of surprise, the focus can and will most likely shift to other victims in the area, giving you time to draw and fire before maybe even they realize they are shot. But again, you can be in a one on one situation where you will be given no choice, and maybe in the case of open carry, simply having it would cause the bad guys to just 'skip' you in an attack and leave.
But anyways, what do you guys think? Does OC show your cards? Is it viable for self defense?
Did you mean CC'ed? Also, common people thinking you are a cop is NOT a good thing. It just reinforces the "only ones" mentality they get indoctrinated with through movies, media, etc.
I agree with some people that have pointed out that the "element of surprise" is more suited to offensive tactics. It provides no deterrence (criminals can't fear what they don't believe is there), so it would remove the possibility of a criminal wising up and an attack not even taking place.
You appear to know the general benefits and drawbacks of each, so I am unsure as to what aspect you are as yet still unsure of. The three explicit questions are a bit too broad.
What I think: "Speak softly and carry a big stick" applies well here (just please, no phallus jokes; I got a bunch when I was discussing OC with my non-carrying friends and acquaintances). By letting the criminal know you are armed, you give them the option to stop, turn around, and find another target or area to target. No "warning shot" is better than a plainly visible holstered firearm (besides, they are unnecessary and reckless, despite what Hollywood likes to portray). Any choice the criminal makes (assuming they have seen it) is fully informed. So in that sense, you are "showing your cards", but they are very strong cards, and the criminal knows it. Bluffing with weak cards will likely only lead to their humiliation.
If they are already attacking and haven't seen it, the case becomes very similar to what would happen with CC, and you may need to use your firearm depending on the circumstances. A bank robbery? Only if the perp/s have shown a willingness to end innocent lives. Otherwise, there is no need to risk your life or encourage the perps to open fire if they can be sent on their way with the bank's money (which is replaceable, and insured). In any case, I guess that part applies to anything that can be replaced (wallet, money, car, etc.).
As to OC and CC being a viable method of self defense, there is not debate there on my part. Even CC (possibly difficult to uncover under stressful situation) is better than not carrying at all. How you choose to carry is your discretion, but it may be heavily influenced by the circumstances.
But keep in mind you are on OPENCARRY.org. Thank you for serving what remains of our republic.