Does runaan's hurricane's bolts apply life steal?

Yes. They deal 50% of your total AD as damage which triggers lifesteal, so if both bolts hit, it's like having double your lifesteal. However, since the bolts don't crit it's not actually as good as double lifesteal, but it's still pretty good. Runaan's + BT is a strong combo and that's why Kalista is so strong. She can dash around to avoid stuff while lifestealing like crazy.

For additional info;

http://leagueoflegends.wikia.com/wiki/Runaan's_Hurricane

So with BT + Botrk + Sprit Visage it stack 36% lifesteal ((10+20)*/1.2)), in the best condition (without crit), do i have 72% lifesteal ?

yes

Does the new runaan's with the critical strikes applied to the secondary bolts also apply lifesteal to the secondary bolts?