The chance of getting to 10+ is (1/2) to the power of 10
So thats 1/1024

So if you try 1024 times, you can expect for it to happen once.

So the chance of failing is (1023/1024)^1024 so probability of total failure after 1024 attempts is 37%

Will take hours to get all your gear to +10, but thats the math. Not too bad eh.

as i haven't put any points into the crafting ability i dont know the answer first hand but i would assume that it does not effect enchanting/upgrading

No, thats for forging your armour and weapons.

It also helps with making potions, runes and more complex materials. Pretty much all crafting benefits from that skill. But, oddly enough, not upgrading.