As for water, lots and lots of platypus’, but I have to admit that after the sierras I hated them and switched to nalgene’s and gatorade bottles (the bags started grossing me out). The amount of water carried depended on how far the next water was. I would say my max load was something like 7 liters, I had a six moons design pack and even though it wasnt ment to hold that wieght, it still did a great job and took the extra stress well. I think my heaviest load was coming out of Tuolomme Springs/ Mojave, I remember hating life a lot that first day! You will probably just figure out your water needs on the fly. I always carried at least an extra liter as I drank more water then the average person out, and even found myself out of water, thirsty and still not close to the next source.
As for clothes I wore a REI sun shirt (button up) with sleeves that you roll up or down. I loved this shirt. I started with a lame X armor shirt and quickly found the sun came right thru it, and I wore lots of sun screen. I did opt for regular running shorts though and I was glad as they are lighter and dry faster then cargo hiking shorts.
I always carried my precip, I hated the thought of getting wet, but I didnt need it until Oregon or so. But I was pretty miserable the first week (cold wise) because it was getting really cold at night. Even with my down bag it was chilly and hard to get moving so I would ditch your fleece or down until you are sure you dont need it.
I was a 2007 hiker so no snow and no need for an ice axe. I did take a course pre-PCT and would suggest it to everyone. I took a course in Mammoth through SMI and it was awesome. I even met another PCTer there. I used the same shoe, brand the whole trip until snoqualmie pass (merrills and then went to Salomon).
Hope those help.
junkfood