Maybe have an option to unlock the tracking of homers and seekers (in case your target is straight ahead or some other reason)?

Well... I think that was intended. Each "missile" class is meant to have its advantages and disadvantages. Giving seekers or homers two fire modes would only result in nobody buying rockets anymore.

Homers/seekers cost more per shot and rockets should do more damage...

Rockets should do more damage? Boy, isn't that a switch. :)