the radiator on my truck recently started leaking significantly when i turn off the truck after a long drive. i pulled the radiator and the fins are easily broken if i push on them. i imagine that this is the reason i am leaking coolant, but should i take this perhaps as a sign of something more since the radiator doesn't leak under cold temperatures?

 

likely, it's no big deal... if you get the radiator replaced. the fins, and coolant tubes as well, are subject to corrosion and electrolysis (particularly since you're in Santa Barbara) and that sounds like what you're describing. when heated, things tend to expand so leaks become more apparent. Salt water spray is hard on copper and aluminum.
replace the radiator and see how it goes.

 

^^^x2