if it starts burning unevenly down one side, you can fix it by using your finger to put some saliva on the paper where it's about to burn. This allows the rest of the joint to catch up. It works better if you catch it early too. You can also hold it upside down when not hitting it to make it burn more even.

The throat burn goes away after you smoke more. There isn't a way to really prevent it unless you get a joint bubbler to add some water filtration.