1/ It's just a way to describe an area, and they are very definable for statistics.
2/ Here 'wound up' could be replaced by'ended up' both are phrasal verbs which tells you what happened at the end of the story. For example, I wanted to get an honors degree, but I wound up with a 2.1.
3/ Guys who like to work with their hands often have a garage that isn't for their car, but is used as a workshop. This scientist is obviously very clever and can do wonderful things in the laboratory. If he has an idea though, instead of wasting his work's time, he can try the idea out in his own workshop or laboratory at home, usually in the garage. Tinkering is to try different ways to do something to find out the best method or maybe the best settings to use.