Order of Stripping and Sanding; Cupping

Thank you for creating and maintaining this site. It has provided a lot of useful information and clarity on an often confusing topic to me and my wife as we tackle refinishing our deck.

Basic Description:

Deck Location State: Wisconsin
Full Sun, Partial Shade, Full Shade: Full Sun For Most of the Day
Wood Type: Cedar
Mold or Mildew Issues: No
Reason for Previous Stain Failure: Flaking, Cloudy in areas
Previous Stain Brand and Type of stain (Solid, Semi-transparent, Transparent, etc): Cabot Australian Timber Oil Transparent

More Background Info:

Deck is about 2 years old
Most boards are slightly cupped
There is still stain left in quite a few places after applying Wolman Deckstrip stripper to the whole deck and using a pressure washer to clean

Plan:

(1) Sand the entire horizontal surface of the deck with a drum sander and edger to remove cupping and any remaining stain.
(2) Apply brightener (Cabot Problem-Solver Wood Brightener)
(3) Apply stain (Armstrong Semi-Transparent Wood Stain)

Questions:

(1) We are expecting that the drum sander and edger will remove any remaining stain from horizontal surfaces. If there is still stain on the edges of boards, can we use stripper to spot strip after sanding or are our only options to hand sand those areas or apply stripper to the entire deck again?
(2) Our current plan is to use the drum sander to remove all of the cupping so that we have a smooth, even deck surface. Are there any scenarios where removing cupping is not advised? Once removed, is the cupping likely to occur again?
(3) If there is a delay between steps 2 and 3 above due to rain, etc., at what point will we need to reclean and reapply brightener?

Thanks!
Jim