I think:
1. The "party" of churning/burning for sign-up bonuses hurts AMEX, and is effectively propped up by those who don't or can't churn. I think this practice is therefore unfair and clearly not what AMEX intends to achieve. AMEX should stop doing this and come up with a better idea that will actually retain card holders.
2. The sign-up bonuses is intended to attract new users who will continue to use the card after the bonus earn. AMEX could, for example, spread-out the bonus earn criteria to something like $1k a month spend out of at least 8 out of the next 12 months - something that would actually encourage user habit-forming and prevent rapid churning.
3. Offers like "small shop" and all might soon discontinue. It makes sense that AMEX encourages us to try to use AMEX for the small shops to indicate that AMEX is now widely accepted (both to the cardholder and to merchants that are yet to sign up) - I myself have been surprised by the fact that some local small shops actually accept AMEX without surcharge. Now that it is becoming more widely used and accepted, there may no longer a need for such offers.
4. I think if the merchant fee is dropping as per law, then businesses like RewardPay should pass on the drop in order to be relevant and viable. Users of RP should contact them to voice this opinion.
5. It makes sense that point-earn rate should be higher for cards that have a higher annual fee.
6. Once the points-tier differentiation is gone, lots of cards can be consolidated and disappear from being offered altogether.
7. Rewards like offers and airline conversion bonuses can be offered for loyal users who spends a certain amount every year or who appears to be using the cards on a regular basis.
8. AMEX can hire me to discuss these great ideas