Thanks everybody for your replies! Seriously, as a mostly solo hiker it is always cool to get feedback from the BPL community. Very much appreciated.
@Nico: Your recent Channel Islands trip report was the final motivation I needed to take this trip. Fortunately I didn't get the windy conditions that you endured that one night. I will check out some of the islands to the north next year.
Finishing the Catalina Marathon on those fire roads is impressive. Everything I read beforehand stressed the challenging climbs. I did the math on the elevation gain per mile and it is crazy. Much harder than the JMT:
@Craig: There was a medium sized group at Parsons Landing that was spearfishing all morning. Freediving, surfing Ben Weston, fish cookouts and sleeping on the beach. Doesn't get much better.
@Roger: Having done San Gorgonio I agree that those never ending hills on Catalina were more of a daily challenge.
@Dave: I did this trip in February, just after a week of rain and it was beautiful. The lows on the beach at night were mild but it got up to 88 most days, and it felt like a desert. Anything after March can get well in to the 90's.
I took my wife back for an overnight at Little Harbor in July. She suffered in the 95 degree heat on the hike out.
A good strategy is to go southbound. Most people go northbound from Avalon and suffer. The southeast facing slopes on the climb out of Avalon are brutal in the morning and afternoon.
I started at Two Harbors and hiked to the north end at Starlight Beach, then camped at Parsons Beach. Water and fire wood were waiting at Parsons Beach (included in reservation). This was the longest stretch without water. ~13 miles.
From Parsons I took the flat 7 mile trail along the coastline back to Two Harbors. Picked up a food resupply (they will hold it for you at the visitor center) and hiked to Little Harbor. There was water at Little Harbor. ~14 miles.
Next day I hiked to Blackjack Camp in the interior of the island. Great sunset views! There was water and food at the Airport in the Sky and water at Blackjack. ~13 miles.
Last day I hiked to Avalon. There was water at the Wrigley Playground along the way. Once on the ridge it's an easy downhill hike all the way down to Avalon.
Water sources going southbound:
Creek above Black Point (seasonal)
Parsons Landing (with reservation)
Emerald Bay (private)
Airport in the Sky
For ferry logistics first I left a car in Dana Point, then took public trans to San Pedro and caught the first ferry to Two Harbors. After finishing in Avalon I took the last ferry to Dana Point and drove home.