Hey 
TiAm just saw your Tmod note: "Also, spears have bullet and solid. Why?"
If object has "bullet" behavior it doesn't need "solid"?
Generally, it doesn't. You don't need solid to register or test for collisions. I don't see any reason why your spears need it. It's disabled by default in my capx. Here's the manual entry on solid; it might give you a better idea of what it's good for:
https://www.scirra.com/manual/104/solid
"Tmod: You only need 1 spear tube object. I left SpearTube2 in the project, but frankly, I see no reason for it's existance."
As you may have noticed spears appear to fire from tube 1 and into tube 2. If I clone tube 1 and use this as tube 2, that tube would have all the behaviors/ variables as tube 1 wouldn't it?
So i thought it easier to have that extra object, instead of going through and removing the behaviors/ instances from tube 2.
Ah, I see. I didn't realize that was an intended function. In that case, go ahead and use it. Maybe give it a slightly different name so you know what it's supposed to do (SpearCatcher?).
Actually, if spear tubes always have a corresponding spear catcher, you could disable my logic that tests for arrows overlapping Bloks and TiledBG_Bloks, and move the actions there to 'On Collision with SpearCatcher'.