EU could make exceptions in situations like this.
If Russia wants to play imperialism again, I can see a "fast track" scenario where Turkey and Ukraine could join the organization in little time. Both nations have a high HDI (in fact, Ukraine is more developed than Turkey).
This would basically make the CSU run amok in Germany. In fact, Seehofer would probably prefer a Ukraine which is fully annexed by Russia over a Turkey which holds full EU membership. 
Don't know. After this we will live in other geopolitical scenario.
And I don't think that bavarians would prefer Russia over Turkey.
Until the US cancels restrictions on oil exports, you are, unfortunately, not in much position to talk.
Could you expound on why the US not exporting oil matters (and keep in mind it is exporting quite a bit of finished product to Europe.
