Welcome, Tbabs!
@Tbabs:
It says that fighters have an attack value of 1 and a defense value of 2 and that bombers have no attack value. Do the bombers have a defense value? If so what is it?
The bombers’ defense value is irrelevent, since they’re attacking, not defending.
@Tbabs:
Can defending fighters shoot down bombers, or only the escorting fighters?
Since the “combat is resolved in the same way as a normal combat”, all of the defender’s hits must be assigned, and the owner of the attacking planes chooses which units are casualties. Normally, this would be the escorting fighters, if any.
@Tbabs:
If a strategic bombing raid is occuring and there are no escorting fighters, can defending fighters still fight the bombers?
Yes. “Any or all defending fighters based in a territory that is strategically bombed can participate in the defense of the industrial complex.” There is nothing in this rule that links fighter defense to the presence of attacking fighters.
@Tbabs:
Most of all, under what circumstances would it be advisable to send a fighter escort along with your bombers?
When there are fighters in the territory being bombed that could potentially defend against the raid. If there are no fighters in the territory, sending escorts is pointless, as they will serve no purpose.