I've experienced 3-class plane on 2-class route. F is usually closed off with no pax. On one heavily overbooked occasion, some J pax were seated in F (sky-cruiser seats) with J service.

Regarding the ICE point: you can still have an 77W, just sometimes with older generation of ICE with the lower selection (A6-EB*). However, some of these have now been retrofitted with wifi and live tv while newer aircraft have not (yet).

I don't think there are any deep recline J seats left in the 777 now that the last 777-200 has been retired.