New Pipe Smoker With A Question? Ask an Old Fart

[Nick]

1) IF they are in baggies right next to or on top of each other the flavor profiles may change a bit depending on how long they are in such proximity. If you have a say a straight virginia lying under an english or balkan the Virginia may carry some undertones of that blend. If they are fairly well separted I think you should be fine.

2) You do not need to and shouldn't keep a humidity control (like a humidity disk, I am assuming) with them. Pipe tobacco should be kept at much much lower humidity levels than a cigar. If you forget about a bag or tin for a few months and find that it has dried to a crisp then there are ways to re-hydrate it and bring it back close to normal.

3) Pipe tobacco does age very well in fact. There are slightly contrasting opinions on this matter however. Some distinguished tobacco blenders feel that a little air is necessary to facilitate aging. However there are many who believe that the oxygen could cause mold to grow rendering the tobacco un-smokeable. My opinion is that when I will age tobacco that is already out of the tin I will store in a mason jar that is air sealed but leave a gap from the lid to the tobacco that way there is a bit of air but when the tobacco eats up that oxygen it will start the aging process. (this last part is my own opinion I follow from reading articles on the matter)

this is a very good website that may help your understanding.
http://agingfaq.nocturne.org/

Cheers and happy puffing on that new tobacco.