On Fly Lines:
I clean them daily if in Salt water use.
I replace them when dirty, cracked or not performing.
I do not seem to have a lot of memory from storage on the spool unless the fly line needs replacement.
It is possible to twist the line whilst coiling and storing it.
I do believe that routine cleaning helps the line last.
I usually keep the heavier butt section in tact and replace everything from there down religiously.
I replace all Tippet after every significant fish. (always on Atlantics).
Terminal Tackle Failure is unacceptable and the direct responsibility of the angler.
I try to Tie near perfect knots, if the wraps don't come together right I cut it off and re tie the Knot.
Sure, I use a lot of tippet, but I don't often lose a fish for a bad knot. (wish I could say it was never).
We have limited time to Fly fish, I like to get it as right as I can.
The Rest is Up to The Fish!
A wet fish is a Happy fish