Will a 12 ga 28" barrel be good for trap/skeet/clay?
Will a 12 ga 28" barrel be good for getting into hunting down the road?
The short answer is ......yes it will
The longer answer is....that while it will suffice for both mentioned activities, it will generally not be the best choice for either. Similar to buying a pickup truck - not the best choice for long daily commutes from a gas perspective, nor the best choice to race at Daytona -but it COULD.
Pumps are great because they are a jack-of-all-trades gun; however they tend not to be a master of any. So, if your usage is a casual one for clays and hunting, go enjoy it and have fun. If you start to develop a hankering to really get into clays or hunting, you will realize that a more "mission-specific" gun will give you greater success.