You will have to define better. Both are excellent rifle cartridges. The 30-06 may have a slight advantage at extreme long range, the 6.5 has a lighter recoil.
No
Without knowing your intended use, there is no way to answer.
If you are receiving 07 percent is better than 06 If you are giving 06 percent is better than 07
Define 7mm. Do you mean 7mm Mauser ( a little less than 30-06), or 7mm Magnum, (a bit more than 30-06)
25-06: The 25 means that it is a 25 caliber. The 06 means that it is a longer bullet than a regular 25 caliber bullet
The .30-06 is a rifle cartridge.
The .270's more of a varmint rifle. It'll tear up more meat than the .30-06 will. There's also a lot more choices of ammo with the .30-06 than with the .270. And I've been in little hole-in-the-wall stores that had .30-06 ammo but didn't have .270. So I'd get a .30-06. View the discussion for this.
Those that fire a 30-06 cartridge, or a longer cartridge. Shorter than the 30-06 is a short action.
First, it is rifle, not riffle. Second, no, or we would shoot tanks with a rifle. Cannon are more powerful. Finally, depends on the rifle. I have a .22 rifle and a .44 magnum pistol. The pistol is far more powerful than the rifle. I also have a .22 pistol, and a 30-06 rifle. The rifle is far more powerful than the pistol (in THAT example).
The cartridge itself is. It has a flatter trajectory than the .308. As for the rifle itself, it all depends on the tolerances and build quality.
06
The 30-06 CARTRIDGE is larger, and has more power than the 30-30. The size of the rifles that fire it can vary a great deal. Both fire a .30 caliber bullet, but of different lengths and weights. The cartridge case of the 30-06 in much larger.