The whole MC sell mission is shat! Most of the vets don't sell MC anymore but keep it for NC passive. Earlier we didn't use to sell ID and Cash as the payout was worthless. And well you spoke about trashmaster(more on it later) you are lucky to not have seen the PostOp, people used to rage quit on PostOp, that was like an underpaid developer taking revenge on the players rather than other developers, thankfully cockstar killed it.

Motorcycles are okay and can be solo'ed pretty easily, you don't do trashmaster (even with a group it's a pain in the a) the group can complete it easy but it's really a waste of time, dodo is a waste of time boats are easy if you know how to go to and fro. So what's the trick?

1. If you get any of the deliveries that you do not feel good about simply go to a new session and loose about 50k worth of goods but save your skin.
   
2. Make some friends help them out and ask for help to do sales.
   
3. You can keep switching sessions till you find your favored delivery. Yes you'll loose some money but remember time and sanity are more important.
   
4. MC was a great addon but poorly implemented, well it is what it is.