1) Feet - No. I think it is very inconvenient for hand/arm muscles and stretches them uselessly, thus increasing risk of CTS (almost all articles about CTS recommend flat or even negative keyboard slope)
2) Wrist rest - Yes. Before I came back to historical keyboards/keyboards with higher body, I did not use wrist rest (I was using low-profile keyboards e.g. apple magic keyboard, where wrist rest is not necessary) After I did though and started to test mechanical keyboards including old ones, the inconvenience of typing position for my hands struck me immediately. The key level was suddenly too high above the desk.
I usually maintain proper "ergo" position of my hands with wrists floating freely above keyboard (not supporting them by rest or desk while writing) but yet still I needed to rest my wrists in between writings or sometimes I like to change my writing position due to monotony and resting wrists on a pad while writing. So I started to use wrist pad which I made myself from old piece of wood. I do not mind that it is hard, I like the touch feeling more than soft (silicone) one I owned historically. And it is also important to rest your hands on your "palm belly/thumb belly", never on the wrist itself (on tendons), otherwise you also risk CTS. I cannot imagine using higher-profile (or traditional) keyboards without wrist rest now.