RKeenan, in both cases I expect what your pup is doing is called "object guarding" - in the first, he's obviously guarding what he has in his mouth. In the second case, I think that he is location guarding.
There's good news and bad news.
The bad news is that this can be quite serious. My grandmother (God rest her) once had to get 8 stitches because she reached for a sock that she had dropped and a cocker spaniel had claimed as his.
The good news is that it IS treatable.
Personally, I really think you should consult a trainer. Make sure it is a positive trainer - older, punishment-based methods may well make the problem worse. I do think professional help is the best way to go in this case.
If you can't go that route, I recommend the little book called
Mine! by Jean Donaldson. You won't find it in stores, but can order it online. The article below is much less in depth, but uses the same basic principles:
http://www.clickersolutions.com/arti...ctguarding.htm
Basically, you want to teach pup that you approaching when he has a valued item is a Good Thing For Pup.
You also want to teach him a "drop it" command. Have a look around the clickersolutions website - there is a wealth of excellent information there!
Good luck!