If you want it to be moist inside you do - browning sears the outside and keeps the flavor and juice inside of the meat.
No.
No, however you may want to sear (brown) the outsides before placing it in the crock pot.
Early preservation of meat products included sealing it in a crock and covering with cloth or leather tied to the top of the crock.
You can, but a meat loaf would be better baked. With a meat loaf you need to mix the meat with eggs, bread crumbs, spices before putting in the pot. Throwing in a frozen chunk of meat means you will just get cooked ground meat. Crock pots are good for a roast, chicken, ribs, Swiss steak. You would cook it on low for 8 hours. Watch the spices because in a crockpot they get stronger and make sure you have enough liquid so not to burn.
No, just put it in the freezer
Let it finish cooking. A decent sized chunk of meat in a crock pot should cook for 8 or 9 hours.
Yes, but not to fry. What do you mean by grease? Are you talking of the kind of grease used in axles? Or the kind on bicycle chains? Then no, you can't. If you mean grease as in "oil" or "fat" then yes you can. Butter, olive oil, canola oil, vegetable oil, margarine, etc will all work fine in a crock pot. But remember, unless you have the special kind of crock pots where the crock can be put on a stove top, the crock pot will not brown any meat or vegetables put into the pot. It will merely cook them slowly over a long period of time. It is best to brown meat or vegetables in a saute pan, then put them in a crock pot. That is where you would want to use the fat or oil. If you just put regular oil into a crock pot, the food will be very greasy if you put in too much. It will not evaporate away as will water or broth.
Yes, you can... you can cook about ANYTHING in a slow cooker.
While it is best to defrost meat before putting it in a crock pot, it is possible to produce good results without prior defrosting. Set the frozen meat on top of a layer of prepared root vegetables. Set the slow cooker on high for one hour, to bring the heat up to cooking level quickly. Then reduce to low and allow to cook according to directions for the size of the roast. A 3 lb. pork roast may require 8 to 10 hours if started frozen.
yes
eggs, milk, meat, produce, bread
Always keep raw meat at the bottom of your fridge and covered. This ensures that should the meat leak, it doesn't leak over other foods.
I would only trust any meat left in a crock pot on a 70degree kitchen for a few hours.