Shocking your pool isn't required, except when you have issues; many people, who maintain their Cl/CYA ratio, never shock at all!
Shocking just means to raise your FC up to shock level, and maintain it there until you pass the overnight drop test and have <.5 CC
Personally, if your water is clear, and you didn't let the FC stay low long (less then 6-8 hours maybe), I'd just raise FC to above 5 and keep it there- but Watermom is more proactive and shocks before problems...
I wait and try to "squeeze under the curve" of problems...
As far as the POOLIFE bag, we need to know the actual chemical name of it to tell you how good it is (or isn't)