I don't know what mechanic friends you guys have, but everyone in the PacNW that I know are mechanics of over 10-30yrs. Have always said to use locktite on flywheel bolts. Then again these are guys building 9-10sec race cars. I have always been told to use it and I do. Never have had a flywheel bolt back out, but have seen them back out.
Dangerous to say the least when your screaming 9-10K rpms in a little civic and your flywheel bolts back out, o man that shi T is like a kodak moment. I have seen numerous Fly bolts back out, even when they were properly torqued down. It's just a safety factor. I will say that I am +1 for Locktite