Very true. Obito's story has solidified one thought for me: for all their natural gifts, the Uchiha are pathetic. The lot of them appear to be bitter, self-centered, unrealistic, and emotionally weak. Itachi and Shisui might be arguable exceptions, but as a bloodline their clan is exceedingly flawed.
I tend to view people who profess to know what my best interests are with enourmous suspicion. Especially, from the standpoint Obito does. What Obito seeks to do is absolute tryanny wrapped in a nice words. Living would lose all meaning, and everyone existance would be dependent on those controlling the genjutsu. Would each person live in their own person fantasy where nothing is real? Would it be one single reality and if so how does everyone get what they want? Moreover, this skirts the massive amount of pain and suffering he has inflicted on his way there. Necessary sacrifices, I guess?
As for the bolded, it's interesting you'd choose that language because it's exactly what I was thinking when I read the chapter and then some of the comments here. The idea that there's anything sympathetic or benign about the desire to strip individuals of their freedom and replace it with control by some entity -- whether it be The Government or a benevolent overlord -- is repellant to me.
I agree completely that Obito's motivation is basically tyranny. It appears that to his thinking, his means -- to force a false existence on others -- justifies his end, which is to be with Rin. He doesn't care about the needs or feelings that anyone else might have or choose -- including Rin, apparently. I mean, is Obito really so desperate that he would take Rin any way he could get her, even if he has to construct a fantasy world where he can control her feelings as well as her existence? If that's the case, just... ick. Ick.
Perhaps he simply wants to construct a world in which she still lives. That would be a lot less creepy but no less misguided, and the methods he has used to pursue that goal would surely sicken Rin if she knew.
I agree that it must have been Obito's feelings that awakened the Mangekyo. To my mind, it would make no sense if Kakashi could influence the bloodline limit in that way. He can use the Sharingan, and control it to the extent his own chakra allows, but influencing its core functionality seems like a stretch. Just my opinion.
I think the fact that Kakashi was crying when he killed Rin was meant to show his personal feelings, whatever they may be, and meant to prove that he was deeply affected by what was happening. Limiting his reaction to tears, while Obito's reaction upgraded the Sharingan, would make more sense.

I think it's far more realistic (and likely) to assume Kakashi collapsed from exhaustion, not PTSD. The P in PTSD stands for post, right? Meaning the stress shows up later -- post-trauma, not in the middle of it. While trauma could possibly explain Kakashi's collapse, I disagree that it could be considered PTSD on the spot.
Exhaustion just makes more sense. We don't know how long he had been fighting by the time Obito arrived on the scene, and then the Sharingan went MS and may have quickly drained whatever energy he had left. Exhaustion is something we know Kakashi has consistently suffered from when using the Sharingan, so that would be consistent.
And as a side note (this isn't directed at you, Codus, but in general)... I don't see how on one hand Kakashi can be considered a cold, unfeeling, rule-bound SOB who was willing to abandon Rin, and then on the other hand could be thought of as being so traumatized by his own actions and Rin's death that he would suffer complete amnesia or forget he's capable of MS. That doesn't make any sense to me at all.
If anything, for me this chapter separated the men from the boys, so to speak. Kakashi comes off as a lot stronger, centered, and aware of the requirements and responsibilities of a shinobi than Obito at the same age. Kakashi took the lumps from his difficult childhood and struggled to overcome them. He may have over-corrected in his zeal not to repeat his father's mistakes, but when he saw the error of being an over-correcting hard ass he worked at fixing that flaw as well.
Obito's response to his emotional lumps was to crumble in despair, and then indulge in a fantasy born from Madara's manipulation and his own psychotic break. I'll take Kakashi's flawed humanity over self-involved, whimpering Uchiha drama any day. But that's just me.
Well, Kakashi's survival is mostly due to his importance to the plot

Obito's short-term revenge was focused on the Mist Nin who engineered Rin's circumstances, then he skipped over Kakashi either because of former friendship, understanding he had no choice, or just emotionally numb indifference. Then Obito focused his long-term revenge on the world in general with the intention of neutralizing its ability to inflict pain.