Well, I suppose that guitar playing is my main deal too. I just mistook when chose career. Now... I love my family, I like to spend time with them and I must work hard for our well-being. So, I can't do to my guitar would be something more than life's hobby, though I can afford some gear. I'm glad that you chose right job, and just go on it!)) Yeah, I've already looked that video. Excellent explaining, man. I liked it and subscribed.
Yeah man I feel ya on the privilege. I've dedicated so much time into it because like anything else in life, you get out what you put into it. So instead of hittin the club or buying the biggest subs for my car, I sit at home and practice. Now I'm able to give lessons tho! I don't have many pupils, but hey it's a start! My biggest problem is gear right now. I'm so broke just tryin to survive workin 40+ hrs a week and lessons, it's really hard to get ahead. Oh, now I won't get offended if you don't look, it's not super amazing. But I have a YouTube channel! Now I am only working with movie maker so please forgive the super cheap effects if you do watch it, but I'm doin the best with what I got =]
It's a lucky to be able practice so much. I can practice only about 8 hrs a week, so I change strings once per month or at least a two months. That is every 32-64 hrs of playing. Yeah, "ESP recommends that you change your strings at least every 20 hours of playing time", but that's realy too expensive for me)). So, it all is the reason to wipe the strings after each use, it realy prolongs life of the strings.
Whenever I see any gunk on the strings. It depends on how much you play. So for me. I practice anywhere between 4-10 hrs a day. I change strings as often as every two weeks. But as low as once a month. If I had the money it would be every week or just under.