Yes.
Yes.
Yes. All small values 1,2,3,4 and 5 cents are readily available at the Post Office. I am not sure about random values like 11 or 24, but you can put multiple lower denomination stamps if needed.
Yes the post office sells 10 cent stamps. Stamps are available in a wide variety of denominations and not all offices will have a full selection. You can mix and match as necessary, so if they don't have 10 cent stamps, you could buy two 5 cent stamps.
No, but you could buy some 5 cent stamps and make the current 44 cent rate.
Sure. Any post office in America.
Yes but only from the United Nations post office in New York City.
They do print 13 cent stamps. You can probably get them at the counter at your local post office. If they do not have them, you should be able to purchase them through the USPS web site.
In the US you can buy two 10- cent stamps, four 5-cent stamps. five 4-cent stamps, ten 2-cent stamps or twenty 1-cent stamps for 20 cents at most post office windows.
Officially the 'Adopt-a-Shelter-Pet' stamp/s are called the 'Animal Rescue' stamps with the subtitle of 'Adopt-a-Shelter-Pet' on the stamp. The 'Animal Rescue'stamps were issued (April 22, 2010) as Scott Catalog numbers4451-4460. These are cute stamps with pictures of cats and dogs. Yes the Post Office did stop making these stamps, but you still can purchase these stamps from dealers at a reasonable price.
Mauritius 'Post Office' stamps was created in 1847.
No, you can not resell your stamps back to the post office.