It looks nice for a first try.
It would make a great projectile too.
It isn't hard to make it fpsc compatible if you saved it as an X file.
Just look at the other entities in your FPSC entitybank folders and you can see what you need...
.bmp for the Thumbnail
.dds for a Texture (can be tga or jpg too)
.fpe for the Properties of the entity
The .dbo and the .bin files for your models will be created at runtime by FPSC so don't worry about them.
Well, unless you have edited your model or one of its files, then you need to delete them and let the engine create new ones to see the changes.
Its all searchable, so you can find lots of info on this and the UV.
Or you can try
Entity Worshop if you want an easy way to do it.
Can't wait to see what you come up with next.