3. Did you have any formal training in order to become a writer? Classes? A degree?
The short answer is no.
I do, by chance, have undergraduate degrees in English and history, but I didn't take any class in creative writing during college that wasn't a requirement for graduation. Later, I took a game-changing class in writing science fiction and fantasy as an adult learner at a place called The Loft, but I'll talk about that in a second.
I think that more important than taking classes about the craft of writing is the act of reading. If you want to write, you MUST read. You should read everything you possibly can in any genre that excites you. Ideally, you should read widely in non-fiction as well.
I think that you can learn a ridiculous amount about our craft by reading. Now that *I* teach the occasional beginners' class on writing, I've found that people who read voraciously often have a "natural" ear for writing. (I put natural in quotes, because I think that the idea of talent is suspect, and that most people who come off as having innate talent actually have been students of the craft in some other way, such as being an intense readers or growing up in a house full of story-tellers, etc.)
BUT that being said, I think that a person can benefit greatly from a class in writing. Genre writers often face an uphill battle in academic settings, so I caution you to be prepared to defend your genre (espeically if you write SF/F/H) if your only option for a class in writing involves a university. People local to me (Minneapolis/St. Paul) are extremely fortunate because the Loft exists here. There's also a reallly strong community education/adult education culture in this area, so non-university options are out there for us... and possibly for you, if you dig around. If you are interested in writing science fiction specifically, there are workshops like Clarion that you can pay to attend. Romance writers, should also keep an eye on their local Romance Writer's of America chapter, because very often they offer writing workshops that can be invaluable.
As I said above, I took a class that transformed my life. I'm not even using hyperbole when I say that. I can absolutely credit that class with the beginning of my professional career for a number of reasons. First of all, since I started out as a science fiction writer, I learned a ton about the conventions of my genre. I also learned how to submit my writing (which is a process that can be extremely hard to fathom as an outsider.) But, most importantly for me, I learned the skill of critique and was introduced to peers who became my teachers, my friends, my support group, my gossip klatch, my lifeline.
Out of my class, I started a writers group* that still meets to this day and of which I am still a member, Wyrdsmiths. What I learned on an every-other-week basis from my peers was no less than transformative. In Wyrdsmiths, I settled down to the business of learning to hone my craft.
Wyrdsmiths was my informal, formal education, and I still study at their feet. I don't think you can ever stop improving your craft, and Wyrdsmiths is where I go to do that.
So the long answer: yes. Lots and lots of training....
* My alter-ego wrote a very detailed article about how to start a genre writers' group for "The Broadsheet." You can find it here: Broadsheet Archives.