And lockpicking becomes very viable on master.
Especially if you combine it with blacksmithing and enchantment.

Completely replacing your main skill with a better skill that completely overshadows the skill you wanted to use does not in any way solve your problems.
On the contrary:
I stopped my destruction mage BECAUSE I realized destruction was usless compared to conjuration:
My fire atronach completely BLASTED enemies out of the water while I could barely touch them.

In any case, I have my answers:
Destruction is not viable, so I have no reason to make a non-conjurer mage, and thus no reason to buy dawnguard and whatever the second expansion is called.
Unless they fix this stuff.

Checking back in half a year! See you then.