Verifying What I Think I Should Do

Location: Kansas City, KS
Deck: 5 years old (included w/new home) 2nd story covered walkout, faces east. Has semi-transparent stain of unknown brand on exterior and interior facing railing trim only. Railing slats are bronzed colored metal, railing cap and deck flooring are unstained synthetic wood. Deck and rails abut against exterior painted siding and painted ground-to- ceiling columns.

I am planning to re-stain the railing as described above. Would you be so kind as to verify my plan (thinking) and answer a few questions?

1. Strip old stain - from what I read here I will try acquire RAD stripper and brightener. Notes on this site indicate I can apply with a garden-type sprayer, let sit and then rinse off.
a) Will over spray during application or rinsing cause any discoloration or damage to exterior paint, synthetic wood, metal/bronze colored slats? (Will I need to mask everything?)
b)Is it best to use a power sprayer to rise or will a hose suffice?
c) Do I need to use a wire brush/scrub? If so, while the stripper is soaking? (this would probably mean doing the project in sections so that the stripper doesn't sit too long/dry out?
d) Is the end goal of stripping to literally remove all old stain?

2. Brightener - is it applied and rinsed pretty much the same way as the stripper? Can I apply it the same day after stripping, and does it have any affect on other materials I mention in #1. I will plan to acquire TWP or other top rated oil-based semi-transparent stain on this site unless you suggest something different.

Thanks so much for answering/clarifying.

-Doug