Ok... for your first question, if you're breeding a 100% het blizzard to a jungle -- your babies will be 50% hets -- which basically means that half will be hets, and half won't be, but since there's no way of telling them apart without breeding them once they mature, they're referred to as 50% hets.
As for the jungle thing -- it's a great debate. LOL
Most people seem to believe that it's not a recessive trait (ie. there's no such thing as het for jungle). Although you do have the greatest chance of producing jungles by breeding 2 together, but sometimes jungles will pop up in odd places too (like from your blizzard x patternless pairing).
Any babies from your blizzard/patternless pairing are double hets for blizzard & patternless (or double het for banana blizzard as it's also referred to).
Breeding double hets together produces (I'll use banana blizzard for this example):
6.25% without trait
12.5% Het. patternless
6.25% Patternless
12.5% Het. blizzard,
25% Het. blizzard, Het. patternless (double het for banana blizzard)
12.5% Patternless, het blizzard
6.25% Blizzard
12.5% Blizzard, het patternless
6.25% Banana Blizzard
If you were to breed the double het back to an animal displaying one of the traits (in this case, I'll say that you bred one of the double het babies back to the blizzard parent), you'd get:
12.5% Het. blizzard
25% Het. blizzard, Het. patternless
12.5% Patternless, het blizzard
12.5% Blizzard
25% Blizzard, het patternless
12.5% Banana Blizzard
All of those percentages are actually the odds of each egg having the traits in question -- so while eventually you should produce a banana blizzard out of either of those pairings, there's no guarantee it would happen anytime soon...
Hope that helped a little bit! Genetics can be very confusing stuff
Jen