1. Are there any specific tools, items that you would recommend to a beginner that you have found useful? There is a pretty long list of required tools so I am wondering more about something you might have figured out that works for you. I feel like that is a pretty general question that may have no answer really.
You'll probably find that your required tool list is a good one. The only recommendation I have is about the same as Scorch's: Buy quality tools the first time. Spend a little more now and whimper about it--or you'll be spending a LOT more later and wailing.
2. What job have you found to be the most re-occurring? Is there something that you see often?
Once again, it's disassemble, clean and oil. The majority of simple problems can be fixed by cleaning a firearm PROPERLY and lubricating with a quality product.
3. Do you prefer to work only on specific arms or are you open to most jobs?
When I was actively working on guns for fun and profit, I took everything I could--however, I quickly specialized in Smith and Wesson revolvers, and the 1911 series. I also did bedding and refinishing and tuning of internals.
4. Am I asking questions that don't really matter and need different advice?
Oh, heck no. Ask questions...ask LOTS of questions. The knowledge you gain now will pay dividends later.
5. Has there been anything that you wished you would have known earlier in your career?
Although my actual "gunsmithing" career was short, I have come to realize one thing over the years: The firearms community is a close knit one, and you should always take advantage of every opportunity to learn. Don't overload yourself with pending jobs; it's better to do good work and have a waiting list. Always treat every gun you take in as if it was an heirloom from your family, and treat every customer like they are the most important person you will ever contact. The vast majority of your business and livelihood will come from person to person referrals and reputation for quality work.
Hiding in plain sight...