must be really really set on using a 317 to add all that stuff instead of picking another regulator
It is likely still less expensive than a regulator which includes remote sense, and the 317 has multiple sources. There have been a lot of integrated voltage regulators with separate feedback and sense pins since the 70s, and a vast majority are out of production.
Yes. Adding an OPAMP in the feedback loop is not going to help stability, and its telling that one with external compensation is used in the above circuit. Also the OPAMP in question needs good performance right up to its Vcc rail. I'd bet you could get in a lot of trouble substituting a modern OPAMP in that circuit . . .
Check the circuit again; the regulator is not within the feedback loop of the operational amplifier. There is no requirement other than unity gain stability; the operational amplifier is operating as a follower. The same compensation scheme could be done with a buffer or couple of transistors, but a jelly bean operational amplifier is the least expensive way to get low offset voltage.
The virtue of this circuit is not requiring an external reference, but of course that could be done also. A reference, single operational amplifier, and regulator could implement remote sense rather than voltage drop compensation, as shown below, but the above circuit will usually be close enough.