1) this is compliacated and would likely involve creating alot of new ships that have yet to be created for the SM2 universe. It is unlikely that Colos would have a star fleet but maybe a task force consisting of a cruiser, 2-3 destroyers, 2-3 frigates/corvettes. It is likely that Kubishev would have something similar or slightly more since it is their AOR.
2) IMO Military ships would stay to continue to render assistance until the situation was under control. That is tyipcal of how military ships operate unless there is some other more pressing emergency.
3) Not likely Kubishev would want much Colosian aid since they are very untrustworthy and their allies (Jade-London) are more open enemies of Colos which would mean Kubishev is likely to be somewhat hostile to Colos.
4) Likely a distress call would go out and also likely Jade London would respond. Colos aid would be accepted in a limited way, but what K-L would do depends on what they have in system. If Colos showed up like the Russians in Georgia there wouldn't be much K-L could do. However, Jade support would likely not be far behind and Colos would have some difficulty taking control of the system for long.
