I agree that TPG overvalues UR points (as well as some other currencies IMO). But, UR points are clearly worth at least 1.5 cents each if you hold the CSR since you can do a direct redemption against cash values at that price. Whether you want to push a bit higher than that depends how much you value the various transfer options.

For spend at Marriott properties, I think the Marriott or SPG card at 6x is still probably a bit better than the CSR, but it can vary. When SPG was independent and the choice was 3 UR points vs 2 SPG points, it was a close call, since SPG points (prior to having the 1:3 transfer to Marriott option) were worth somewhere around 2-2.5 cents each, vs. 1.5+ cents each for the CSR. Assuming new Marriott points remain similar to current Marriott points in being worth around 0.8ish cents each (a value TPG uses which I think is about fair, though I could see an argument that it's too high), then 6 Marriott points would be equal to 3 UR points if you valued UR points at 1.6 cents each. Either one is a fairly good option though, and in part the answer may depend on how rich you are between the two currencies at any given point in time.

The AA card question is similar. In theory 3 UR points should be worth more than 2 AA miles (which I believe is what your AA card gives you on AA spend?). 3 UR points can be converted, for example, to 3 UA miles, and even if you think AA miles are worth more than UA miles, I don't think they're worth 50% more. But it also depends how rich you are in each program, and what specific awards you may have on your radar -- if you really want to fly Cathay Pacific then 2 AA miles may be a better way to get there than 3 UR points (you could transfer UR points to BA and redeem for Cathay via BA, but BA charges many more miles than AA on most longhaul trips, and BA also charges higher fees).

And of course, don't forget that if you buy an AA ticket using the CSR, you'll still earn the miles for flying the AA flight, you just won't earn the extra 2 AA miles per dollar for the charge. So if you fly AA fairly regularly you may find you earn enough miles from the actual flying that you're happy with that and prefer to put the charge on the CSR.

Arguably, though it is counterintuitive, if you really want to continue using the AA card, it might make more sense to do it for non-bonus spend categories -- no matter what valuation you put on both currencies, 1 UR point vs 1 AA mile is going to be a closer call than 3 UR points vs 2 AA miles.