If you feel that your offer that, quality instruction, then go full steam ahead and you have my best wishes.
As for your musical inclinations, I have no beef with metal, tho' I don't particularly like it, but my feeling is that a guitar teacher ought to have a broad musical base, both in terms of what interests them and what they can play to a convincing technical level. I guess you could specialise and still do well, but I'm suspecting you'd do better if you had more variety.
Or may be I'm jealous coz I've owned a guitar for close to five years now, and I'm not anywhere near considering myself as qualified to teach.
Anyhow, good luck with the lessons.
