@Ozymandiac:
Can a tactical bomber be sent on a SBR when it cannot do any damage?
Yes, technically it bombs the ruins but the additional damage cannot be assigned.
@Ozymandiac:
Does it participate in the dogfight?
Yes, as an attacking bomber (not as “escort”, only fighters can escort).
@Ozymandiac:
Is it exposed to the AAA?
Yes, every attacking bomber surviving the dogfight is subject to the AA-fire of the facility it attacks (other than fighter escorts).
The self-defense antiaircraft ability of the facility is not affected by damage.
@Ozymandiac:
Context: Japan keeps sending 1 tactical bomber + 1 strategic bomber to India, which is defended by 2 fighters. Every time the strategic bomber bombs the factory and the tactical bomber bombs the airport/harbour (the TAC is sent along in the SBR to provide an escort during the dogfight). At some point, the airport&harbour both have 6 damage. Can the tactical bomber still be sent to India?
Yes. There is nothing in the rules that prevents bombers from bombing damaged (to whatever extent) facilities … but damage exceeding the limits is not applied.
HTH :-)