@evilcherry: I'm (as one of the rocket fans) against something Me-163-similar. They're the classical interceptor when we haven't even seen strategic bombers, quite ineffective in their role and we haven't got experience with rockets.
@Bombing discussion: The ability to take bombs is useful even for a pure fighter. Aside from the ability to mount droptanks should we develop them on there, it allows us to support ground attacks once we've achieved air superiority.
See, for example, this turn's invasion: We had air superiority (then lost it by being pushed back). With air superiority, the only thing that could've been done was strafing using MGs. That wouldn't have helped against the ships. Contrary, if the Raven had had the ability for even a modest bomb load, that would have forced the enemy to operate further outside, and thereby limited their artillery capacity.
And yes, the Raven's going to be obsolete - but not due to being a biwing. It's going to be obsolete due to limited speed and armour. This relegates it to secondary roles, that is not fighting with their fighters. What remains is only recon and ground attack, for which it is only equipped with two 15mm MGs. The same procedure will happen with every one of our planes, and did so in real life, too. For example, the Hurricane was relegated to ground-attacks as the Hurribomber, using bombs and cannons.
The problem is, you need a pretty huge number of fighters to achieve air superiority. Once they've achieved it, they only have to fight against a smaller number, and therefore are not needed any more. Giving them ground attack ability keeps them useful. Let's say, for example, that each of us has a hundred planes, and ours are better by a factor of 2-1. This means after achieving complete air superiority, we've got fifty left - of which we need maybe ten or twenty to continue the air superiority (intercept newly built ones.)
Oh, and - what type of bomber after this? From the classical roles, you have close air support (dive bombers, attack aircraft), tactical bombing using longer-ranged (normally two-engined) bombers for interdiction, and strategic bombings (normally using four-engined monstrosities). Which of them do you want?