Stopover has no defined length. Maybe maximum is a year. So a month or 2 is no problem as long as there are availabilities.
You could do AU-SIN (transit/stopover)-FRA/AMS-SIN (transit/stopover) - AU. With the stop over in SIN, take a side trip to Kathmandu.
If you book return via Krisflyer, you get 1 free stopover. Otherwise, its U$100 per stopover.
Yes, redemption with KF has relatively high surcharges/taxes.
Depending on the value you place on Velocity points, you compare that with the following figure:
(Revenue Fare-Total out of pocket cost of award flights)/number of points used for redemption
e.g.: [$5300 (buying ticket with cash outright) - $3250 (surcharges/tax)] / 436,050 VFF = 0.47 cents per point.
Keith’s valuation aim’s to redeem at 1.9cpp but your value may be different. Cpp for redemption of Econ seats are often less than business or first. Hence, why there is a general suggestion that premium seats are better value in redemptions.
IMHO, if you have travel plans in the next 1-3 years, I would use it for first class. For example, AU east coast to EU in first class is 112,625 KF (152k VFF) one way per person. cpp is much higher as you would imagine. Everyone’s circumstances are different so you will have to decide yourself.
Another bonus with revenue fares are, you earn status and points. Plus you generally don’t have to worry about availabilities as much as award availabilities. Which means more flexibility. Stopover becomes free.