I concur with what dvs7310 posted. Yes, if you make changes to the 3rd segment then all other affected segments will also need to be changed.

To the best of my knowledge and experience, if you are only changing date and times AND NOT changing stopovers to <24 connections or vice versus, then there will be no repricing prior to trip departure. Ticket repricing to new fare will occur if you are making changes to your first flight coupon OR are changing your ticketed points. When I made my reservations I always made sure that any placeholders were done with the stopovers and connections I wanted for my future dates. In a few cases I made a couple changes prior to departure on my first segment, especially for routes where A class (in the case of AA domestic now D class) were few and far between (DFW-EGE flights in particular and also ORD-ANC) and A class on QF SYD/MEL-LAX, CX on HKG-JFK, etc.

So, if I booked like you starting in January with end date in August, with (for example with travel grouped in spring and late summer) then I would make a batch of changes in July and another batch of changes in October. Now if you are flexible it may be easier to do changes after you fly your first flight segment as most of your journey's segments should have plenty of D availability; the only exception might be your two ANC related flights depending on the time of year your flying those which I would guess may be somewhere between April and June. I checked D availability on HNL-ANC and ANC-LAX flights and there was plenty of availability throughout May with the exception of about 1, and in some case 2 days a week. If you could easily change your travel plans by one day, then waiting should not be an issue as long as your not flying during a special event/high demand period (think CDG during the Olympics). With most HNL-ANC flights having D2-D4 and most most ANC-LAX flights having D7 availability. I would suggest getting a EF subscription if you don't already have one and do research for this year's dates corresponding to the same period and day of the week for your actual planned dates for next year. That way you have an idea of what availability will be probable for next year's dates.

Enjoy your trip.