Well, there's a bit of an undocumented feature here. If every object in a family has the same behavior - ie. family 'Friendly' consists objects A, B and C, all of which have the 'Bullet' movement - then the 'bullet' tab appears for the family as well in the dialog. If one of them has it missing, it won't appear - if it were there, a 'Set speed' action for the bullet can't be applied to an object that doesn't have a bullet movement, hence the requirement that all objects in a family have the same behaviors for this to work.
I think it might crash in the current build, but if it does, it's fixed for the next build.
I haven't documented this feature anywhere yet. But I hope when/if it works, it satisfies you