Bubbles nests are normal, and yes cute :)
I'm not aware of an "average" age...
Bettas can and will jump over dividers-I had one jump over 2 1/2 inches once. You can always lower your water level.
Atlas blue metallic marble HM
Forest red VT
Leander red/pink dragon Delta
Mister Intelligent orange/white BF VT
Phrixus teal marble dragon HMPK
Psyche blue/red PK
Rhea black/red BF DT
RIP Alexander, Morpheus and Phobos. You are missed :'(