Slitherine

Simple question: is Barbarossa 1942 worth considering?

Gains: conquer of Britain + destruction of the whole RN + capturing Middle East.

Is such conquest worth delaying Barbarossa and as a result facing much stronger Soviets (with no -30% at start)?

It can be - if you get good weather and launch your offensive before the Russians activate it can be a winning strategy, esp. if combined with capture of Persia and the MidEast oil. If done without either taking out Britain or closing the Med and allying Spain it is a recipe for disaster in my experience.

I would say not. If you take Britain and build up your strength although the Russians will attack but they wont get very far. You can beat them off and win the game. By taking the middle east you can attack them on two flanks.