Not really, a very common pattern on SO is to jump on a question to which you know you have a good answer, put something very short (but correct) and then edit in a better, longer response. This avoids "losing" initial votes from people looking at responses while you're fleshing out the description, adding benchmarks, etc...
It's definitely gaming the system, but it's not really suspicious (in the sense of "guy asks a question and immediately puts a response he had pre-written in a text editor" suspicious)
The "suspicious" case you mention is explicitly supported by the system; you can actually write the question and answer at the same time if you want. The normal content rules still apply, of course; if the question isn't about an actual problem, you're more likely to win a bundle of downvotes.
I think without this ability to "game" the system SO wouldn't be half as good as it is now. You end up with brilliant and above all complete answers that can be kept up to date, and the moderation policy reduces duplication and clutter, keeping the SNR high.
Sure, some people might be motivated only by receiving high scores, but it seems that the benefits outweigh the potential for abuse
Doesn't matter. You can answer your own question immediately after posting it if you want. It's designed to be a collections of questions and answers, not a forum, and so it doesn't matter who answers what question.
I often do this. There is one answer which I've been quite literally editing for about three years. Every few months I add a bit more information or a few more references or links to it. Its become a kind of personal (but public) repository of information on the topic.
If you read the post author's comment on his own post, he went back and added all the explanation/analogy after making the initial post that just said it was down to branch prediction.
