Swerve one more point that occurred to me thinking about this. You mentioned that Ukraine tried to tread lightly on the Crimea issue and lost the province. That's not true. Ukraine attempted to move their military against Russian forces in Crimea. They simply failed to. Two air mobile brigades failed to leave their bases, after being confronted with pro-Russian protesters. In essence it wasn't a desire to not move their troops (towards the end they even ordered their units in Crimea to use lethal force, most of them simply didn't), it was a basic inability to do anything. What it comes down to is that Ukrainian force-wielders are for the most part inept, unwilling, and incapable.
The other issue is that the rebellion is capable for a rebellion. The Ukrainian military is incapable for a uniformed military. The rebels are still not capable by general standards. Unwillingness is in many cases a huge issue. Look at some of the events: some rebels show up with crowds of civilians, and military units hand over their weapons and leave. It clearly wasn't a case of military defeat on the part of those units. Look at the second move on Slavyansk. SBU and MVD units attempt to move in, meet some resistance, and refuse to keep advancing without air strikes in support of them. Pilots are routinely refusing to fly missions, and the MoD has moved on to massive cash incentives to get pilots to fly missions against the rebels. There were reports about massive refusals by pilots to fly and rescue a downed pilot. This has less to do with professionalism and a lot more to do with the fact that they simply have no wish to kill their country-men.There are some "ex" russian military in there - and the definition of "ex" is somewhat tenuous
there is a clear question of Ukrainian military competence if they are unable to match up against "militia" forces that are often 80% smaller.
however, footage of ukrainian soldiers the other day clearly showed a lack of basic training