Is there a reason to move the points out of AMEX? Maybe you are closing the account?
If you keeping your AMEX account, then I would say this the best place to warehouse your MR points as it gives you flexibility. Move the required points to your KF/VA/QF/CX/whatever account when you are ready to redeem for an award flight.
Just checking you are aware of the following with KF:
- Points earned in KF expire after 3 years. Cannot keep these points alive by fresh points earning, unlike VA or QF. This is a moot point if you redeem within 3 years of course.
- Moving points from KF to VA (and vice-versa) can be done but at a cost of 30% of your points. So if you did move your points to KF and have not redeemed them after 2 years 11 months, move them to VA. Better to keep 70% than lose all 100%! (This assumes the KF/VA transfer method is still available at that time.)
I do like the KF program, for the reasons you listed. But you just need to be aware of its weaknesses.
For the places you wish to travel to, can these be achieved as KF awards? Redeeming an online KF award, and so qualifying for a 15% points reduction, is great. If you have to book it as a Star Alliance award, then this requires more points and there is no online 15% points reduction.
For the hotel guest program, would you want to be booking hotel awards or flight awards? For flights, SPG is an obvious choice as you can move points from SPG to AA, BA, KF, VA, etc. For more info, check out Keith’s great article about SPG: http://www.pointhacks.com.au/starwood-preferred-guest-introduction/
But there is uncertainty with SPG due to it being acquired by Marriott.
So that is yet another reason for keeping your points with AMEX, until you are ready to make a booking, for a flight or a hotel.
Hope this has been of help to you.