In answer to 1: Probably not, if you only ever made one bet in your entire life, it would be unlikely that addiction could be a factor as most clinical definitions of "addiction" require time to develop. One definition of problem gambling involves the level of preoccupation with the activity in question. A person could still meet several of the criteria in the DSM-IV for disordered gambling and be classified a problem gambler, but only people that meet five out of the ten criteria are considered to be pathological gamblers. It would be very easy to meet some of the criteria without having to ever play at all. You would merely need to think about it.
In Answer to 2: First, your question is impossible to answer because you did not include a time frame. You asked, "who has the restraint/discipline to limit his gambling to a win goal/loss limit" with no reference to time. A blackjack player that is betting $100 per hand is limiting his win goal/loss limit to $100 for that hand (not including doubling and splitting)...and then he plays another hand after that one. A person that has win goals/loss limits but leaves the casino only to return another time is IDENTICAL TO THE BLACKJACK PLAYER in everything but the duration of delay between wagering again.
Second, the word, "addict" and "addicted gambling" are not in widespread use as medical terms anymore. The primary medical calcifications are now:
1. Pathological Gambler (meets five or more of the criteria in the DSM-IV)
2. Problem Gambler (meets less than five of the criteria in the DSM-IV)
Only three of the criteria would be less likely as a result of self imposed limits. The issue that the person imposing those self limitations felt them necessary in the first place, and thought about it enough to create them, would likely make them meet at least two of the criteria. In other words, if a person had felt the need to create and impose such limits, they might be less likely to be classified as pathological, but they would automatically qualify as a "problem gambler".
I'd really like to state here that these are medical terms and you have asked me to tell you how the medical community views this. These are NOT MY OPINIONS. Keep in mind that the medical community considers nearly all gambling of any kind to be as a result of some sort of cognitive distortion, mental deficit or varying degrees of mental illness.