I have an idea for noobtubes.
First, the actual grenade, give it a maximum lethal velocity range, which is about 5 feet from the lanucher. This MLV range means that within 5 feet, you can kill with a direct impact of the grenade. Additionally, have a minimum explosive range of about 18 feet, which is how far the grenade itself must travel before it will explode on impact. So now the noobtube as lethality from 0-5 feet, and 18+ feet. However, this leaves 5-18 feet range as a non-lethal grenade shot, so the noobtube has no lethality in that middle range; in fact, if you hit someone in that middle range, the grenade does little damage (like a single pistol shot to the chest) and the grenade itself drops to the gound and doesnt explode.
Also, take a page from BFBC1&2, and add sights that need to be equiped before firing the GL, and make the GL only capable of firing from an ADS view, like the China Lake.
Also, make scavanger only replenish bullets and shells, while making a second perk that acts like scavanger, but from explosives, limitling it to replenishing thrown explosives, tacticle grenades and maybe RPGs and Stingers, with a slight chance of replenishing noobtube ammo (about a 15-20% chance to get one round.)