To the first question: as a gunsmith, most of the firearms that I put my hands on, other than FFL transfers that I process for customers, come to me because there is problem. And usually, the problem is something that could have been avoided by reading the owner manual. But I digress. Gunsmiths typically focus on the system a particular firearm uses to operate. For example, 1911 pistols use a link to pivot the barrel out of the lock position after firing, whereas a Beretta or Glock use a cam, and most smaller .22 pistols don't lock at all before firing and use all of the energy of the fired charge behind the bullet to "blow back" the bolt. The point here is, when talking to a gunsmith, the better question is, "What kind, or how many problems have you seen with [insert firearm make and model here]?" Opinions are a dime a dozen, but most gunsmiths are better prepared to recall from their data instances and circumstances they have worked on a particular firearm which is much more meaningful inormation than a personal opinion.
To the question of the best firearm for personal protection, there are WAY too many variables to say what is "best" for everyone. Best for me may not be best for a first-time gun buyer. Below is a link to a great video produced by Brownells that goes through the important things a first time gun buyer should think about to aid in having an informed conversation with a sales representative who can help narrow the search for what is right for you.