1) Origin just made a
rocket launcher that can be hand-held, though it is very large and somewhat cumbersome, having been designed initially to be mounted to vehicles, or used as a stationary platform.
2) Ideas are usually linked to the
List of unapproved concepts, or on the page of the company that is going to produce them if they're approved.
3) As for standard weapons templates- there are none. With the huge variety of weapons and weapon types available, no one template is suitable to all of them, so you either have to find an article of something similar to what you have, or just make one up.
Still this is a neat idea, and could have its uses.
Origin Industries, My company, is always looking for good ideas and can make such things as this, and there's generally someone around to help. Myself, and CadetNewb are more or less in charge of Origin, so coming to either of us with ideas could be nice.