Signature marketing is a very common practice. If you actively participate in the forum, this could bring you some traffic.
Absolutely! You may not be able to get tons of traffic from it. However, you should be putting your website/business everywhere you can. Marketing isn't about keeping your website to yourself or only sharing it with a few people. Share it with everyone you know!
Of coure not. Well, rather, if you are satisfied with a few hits or so a day, followed with a high bounce rate. Many inexerienced webmasters, and, complete idiots seem to be happy with so few hits. But, if you are going to post anyway, you might as well put in a signature. Just don't expect much.
If it's good for human (which it is) then it's good for search engines. Of course you might end up getting competition...
Because, AquariusRyan, workers in third-world countries make more money, and work far less hours to get that pay. Getting more traffic is always good, but when you look at it like that.... And, you still have that high bounce rate in many cases. Two things many noobs don't think about. Some say that it is good for Google. Okay, is their site on page one? Two? Three??? It is one of the worst methods. ... Bottom of the barrel. Only clueless noobs and or kids, idiots continue to do this, thinking it works. But, if one posts anyway, he might as well put in his signature. He's got nothing to lose.
I don't see how it could hurt, it is reccomended to use sig's when posting and more.Its more exposure for you.
All depends on the site you're working for, but it can't hurt unless you're posting things about the sites here your competition may decide to use. The "Linkbait generator" link in my signature has been clicked around 200 times this week alone.