Re leg 5
Interesting that CarlF classes the B996 past Bein Inn as "no go" - as much as I like quieter roads I would ride via The Bein Inn then Dron every time and Ive never experienced anything unpleasant (caveat - 99% of my rides will have been weekend mornings mind you and its not one I relish cycling South ie up the glen not down). The road surface is a bit gnarly but overall its pretty much standard audax fayre imho. The descent is a bit twisty and starts just after Glenfarg village I dont recall anything having overtaken me until the straight at the bottom of the glen but nor have I experienced any impatience from drivers either and i aint no daredevil descender.
I agree 100% with not riding the Baiglie Straight (the bit between the RAB near Aberargie and Bridge of Earn) hence my suggested dog left left via Dron to Bridge of Earn.
If you dont mind the lumps and want quit roads then for sure the Wicks o Baiglie road is preferable.
So just to update, we followed the slightly more direct road hugging the M90, rather than dogleg out to Bein Inn, and I got kudos from my guests for the descent down to Earn being the best - straightest, clearest, smoothest road - of the trip so far! Overall it was not a high elevation day so that one extra climb to get to it seemed to pay off well.
That whole part after Kinross, and through Perth, was really pleasant and easy to navigate, so thanks again for the help.
Now... we just need to survive the rain and unseasonably strong winds for 2 final days