Can I brown ground beef in a crock pot?

Yes you can. Coat the pot with oil before placing the ground meat in. Cook for a few hours on low to avoid scorching. It would be best to strain/drain the grease that will come form even lean ground beef. That is where most of the cholesterol and saturated fats are.

Make a really thin patty. Put tinfoil on the toaster oven pan, and make a lip at the edges. Turn the toaster oven to broil. Cook one side, flip and cook the other. Bring it out. Break it up into smaller portions on a plate. Empty the pan of juices. Finish cooking it. You will have tasty crumbles. Whereas in the slow cooker, it will stew and be unpalatable. In the microwave, it cooks unevenly.

I would try the toaster oven before any of the others. Just put in small amounts, and cook it in batches.

Sure,but it might take forever.Good luck with that!