I started playing/teaching myself with my larger nylon string guitar (for 2 years). I only switched to my 3/4 steel string guitar in Jan. 2006. My callouses had already built up at that time. They stung for awhile due to the steel strings, but toughed up after a month. I haven't had any neck issues that I know of. As far as playing 2 hours a day, I just find the time after work to practice my guitar for 2 hours and then learn new songs (being single and childless helps). I usually practice for 30 min. in the morning and do the rest at night.