The place that you are using for maintenance on your car is very suspect, if they have made these recommendations. As was said, a manual tranmission CANNOT be “flushed”, and should not even need a change of its gear oil at 30k.
As to “fuel injector service”, unless you have mentioned specific driveability problems to the service people, this is something that is both superfluous and unnecessarily expensive.
Please tell us where you have been servicing your car. For your sake, I REALLY hope that it has not been Jiffy Lube!