Putin won't care, he will most likely install a regime of Ukraine nationals. As Putin talks of nazis and the need to "purge": this time less like Yanukovitch, more like the brutal Chechen Kadyrow. very depressing
I don’t see Putin being able to build the organs of a pro-Russian state in Ukraine, even a repressive one. The population is far too hostile to the idea, and too militarized.
In my opinion the more likely outcome if Putin doesn’t stop is Syria: total collapse, the civilian population flees and only militants remain.
If by over you mean becoming a failed state and years of subsequent civil war then yes.
Putin will face a similar problem in Ukraine, he can punish it but he won’t be able to hold it because the population absolutely hates Russia’s guts.