Centaurus,
Thanks for again sharing some of your wisdom. I always enjoy your posts.
You're absolutely right - it takes more guts to say 'no' sometimes than 'go'. However, from my (limited) experience, when having made 'go' or 'no-go' decisions, I have regretted going somtimes, but have never regretted staying.
As far as saying 'no' and then feeling like a wimp because all the others got in / out OK, you only need to look at Delta flight 191 (microburst). The aircraft ahead in the sequence landed with no difficulties, but that was of no help to the crew of Delta 191. What others do is irrelevant, trust your gut!