I have 19 booked for next year so far I limit myself to 36-40 a year as I have a very intense full time job and a family. This year I have done 21 weddings so far and have 18 more on the books.
You answered your own question dude "I have thousands of dollars in pro gear, a legal music library and insurance all paid in full from earned profits"
They sure will when they can illegally stream music, illegally acquire music, not p;ay taxes, not pay insurance, and go to Best Buy and buy cheap ass equipment you bet...as much as the laptop made DJ's jobs easier it has hurt them as well because now any bozo w/ a laptop and a streaming music...
Say I'm booked 5pm-10pm I leave @2:30pm arrive around 3ish set up sound check, etc 30 minutes teardown/load up home by 10:45/11 so 8-1/2-9 maybe an extra 45 minutes if i'm on the beach
I have never in 22 years and over 700 weddings cut the cake right after intro's actually have never seen that done...Like I said it's very regional go with what flows best for you. I have always found the first dance right after the introductions is the best it is their moment but again...