How can I seal the edges of a linoleum floor that possibly contains asbestos?
You are far more likely to die from worrying about asbestos than from asbestos.

I just finished dealing with the same thing you are.  Where possible, I installed engineered flooring and underlayment over the linoleum.  They look killer! :)
My mother, a retired cyto-technologist, kind of laughed at me about my own asbestos concerns.  

http://fumento.com/asbestos/asbest.html