If you want to teach others, then by all means go for the DM certification. You don't have to go on to become an instructor, in fact, myself and several of my DM cohorts enjoy the absence of paperwork that comes with being an instructor; when we work with instructors, our DM rating allows us to directly teach skills in confined water and assist in O/W evaluations, kind of a best of both worlds. But if you have no desire to teach scuba, then I'd not spend my $$ on a DM rating. Tec, GUE, and specialty ratings are probably the better alternative to continue to improve your skills and education.
As to being a DM without insurance, no you wouldn't want the liability of teaching others without insurance. PADI also charges its DMs an annual fee to maintain their current DM rating, apart from the insurance costs, and I assume the same is true with the other agencies. All in all, it ain't cheap to maintain yourself as a DM.
As to being a DM without insurance, no you wouldn't want the liability of teaching others without insurance. PADI also charges its DMs an annual fee to maintain their current DM rating, apart from the insurance costs, and I assume the same is true with the other agencies. All in all, it ain't cheap to maintain yourself as a DM.