DRIVING ON ARRIVAL DAY ==
Depends on how old the OP is, and what level of airline ticket they're plunking $$ for.... If they're no more than middle-aged, and can catch 4 hrs of sleep on the plane ... and quaff 2 strong expressos when they land, they can make it to Delphi OK, little traffic on that road in Midmay... check into hotel, catch 2 hrs late-day nap, then go see the Museum from 5-7 (it's EMPTY at that time!) Early bedtime, enter ruins site at 8 AM, again, almost no one there ... you'll be way up top by time the bus-tour throngs pour in.
ARGOLID AREA -- good plan . You can avoid backtracking by saving Epidaurus for AM on Day 5, don't have to stay long, the theatre is the main thing, then drive up the Coastal road to Isthmus, spend 15 minutes by Old Bridge to check out Canal then hit the Big Highway to Athens area.
YEs you can pick up car in Chania, drop in Heraklion NO problem no fee. HoweverI would spend at least !! one niht in Chania!! Loveliest old-Town in Crete!! (2nd loveliest in Greece, bested only by Nafplio). And as long as u have a car, why not go south and enjoy PHaistos enroute & catch a glimpse of Lybian sea? Here's my suggestion based on 3-4 great trips; use this map to track: http://www.explorecrete.com/crete-maps/images/Crete-eot.png (click & it gets huuuge).
Day 6: spend day in Chania, check out museum (maybe eve a late day dip in town beach) harbor sunset, great meal, stay in little pension on Theotokopoulu Street (casa di pietra, Pension Nora many others). No need for car this day.
Day 7 - Car delivered near hotel -- drive modern hiway (Big GREEN road) on Map to Rethymnon area (or do cute inland Old Road & see lots of sheep/goats & little villages), At Rethymnon, Turn south on (Red Road on map) thru SPILI (village with AMAZING ancient lionhead fountains!), continue to MATALA - I recommend Villa DImitra, back from beach, view of mountains. Climb caves above beach, have a dip, enjoy sunset, check out KOMO archeology dig nearby.
Day 8 - In AM, go to Phaistos & Then Ag Triada then Drive thru Mires, on same Red Road, N.E. to Heraklion Area, to hotel.
Day 9 - Knossos & the museum -- some like to do the Museum first others the ruins.. If you do ruins first, get there by 8 AM to beat the cruise-ship crowds. Otherwise, get to site after 2 pm, when cruise & bus crowds start leaving. Fortress on causeway is a fun walk before dinner ... there are fab "meze" places right on traffic circle at foot of causeway.
Day 10 - 14 as stated.