score:3
You should not run into any issues. Your reasons for traveling are valid and totally covered under the ESTA program.
I would just take the precaution of bringing along documents that prove your itineraries (your stays in NY, Toronto, Vancouver, LA, and LV) along with a return flight home. This will just show the border guard that you are genuinely traveling and not planning on doing anything illegal during your stay.
Enjoy your trip!