If you see istif class with gökdeniz,there is no ammunution feeding structure of babur class,so you are right waitng for roketsan or aselsan missile system is seems logical
Babur class will not carry 10 ton heli but 5 ton class.Is 5 ton class heli can carry lightweight torpedo,otherwise anti sub capability could be reduced
Everyone are downgraded the S400 system,but if you have a good layered air defence system to protect S400 then it can be used against large and slow targets,such as tankers,awacs,reconnicance drones,cargo planes,,etc… from very longe ranges,thats a good advantage.