@Jesse Buchanan @Brandon Stiles
I think hiring your own trades is better, if you have the time. Even doing it personally is fine --- that's what a regular homeowner does when getting work done on their house.
I guess it seems I would need to caveat that you are NOT hiring employees. Hire the plumbing trademens (either work for themselves or a plumbing shop), electricians, drywall/spacklers, flooring, painter, hvac, ktichen/bath, etc. They carry their own insurance, wc, etc. While you maybe flipping, I guess I don't jump to seeing this as a new "world" any different than a homeowner wanting to remodel their own home and having to buy their own insurance...
If you have the time to do this, it lets you find and hopefully hold on to the "good" trades, the ones you like and get along with well. Lets face it, the GC is basically doing the same thing. They are just sub'ing out to whomever they know. What if you like half of your GC's trades' work? Sucks to fire the GC and the whole thing to try to find another one that will have a crew that you like.
At least in NJ, the trades still pull the permits, even if they were doing work on a regular homeowner's property. Their license/registration is on the hook.
I know flippers who get their own liablity and wc insurance and put an umbrella on top of it (remember, you need the basic underlying insurance below the umbrella policy). I did it at one time, but that was for licensure/registration purposes. If you have a lLC, you should have something otherwise when/if you are sued, you'll go broke in legal fees defending your LLC, even if there is nothing in it. For some, it make them feel more comfortable should the trade's insurance max out for some reason. Also, sometimes you hire uninsured people, e.g. a cleaning crew at the end, so having the insurance is rather justified at that point.
For better or worse, if you can pay everybody with a credit card, you don't need to file 1099's.. Save you some paperwork. :)
Hope this helps Good luck.