just tell them the truth -- you dad is rich, and criminal at your age won't fly F anyway.

as for your trip, it is definitely valid.
for your second year you might want to buy a 1-way to HKG or BKK or ICN. then you dont need to start from YVR every year again.

if u r using OWE, ex-Seoul is lot cheaper than ex-BKK now, i think