dunno how much you can read into the Mexico adventure. It was a foreign culture that he was totally unprepared for. He'd been told he was coming in by the will of the people, which was a flat out lie. He could have been the greatest ruler of all time, but the Mexicans would have hated him from the start.
Much of the barriers he faced in Mexico would not have existed in Austria. He still would have had a tough row to hoe, but nowhere near as tough as the one he faced in Mexico.
I mentioned some of those issues in my previous post (French aggression, foreign ruler, etc.) However, Maximilian and his court made significant mistakes on their own which sealed their fate. A minor one was an incident where a Mexican woman tried to give the empress a traditional embrace, only for this to happen "the tall Empress stepped back and drew herself up to her full height at what she regarded an undue liberty, while tears of indignation came into her eyes. Whereupon the poor señora was dissolved in tears. . .". At least some Mexicans were willing to support him, including the conservative priesthood who disliked Juárez's anticlerical policies.
His appointees were apparently not much better. His friend Eloin ". . .did not speak one word of Spanish, hated the French, despised the Mexicans, and was more ignorant than his master himself of American questions. . .While in office he used his power to repress much of the impulse given to enterprise by the French." A Belgian diplomat said "To eat priest for breakfast and Frenchman for dinner, when one has been called to the throne by the clergy, and must rely upon France for sole support, may be regarded as a dangerous policy." As for Austria, Maximilian seemed to have pretensions for the throne even though he was supposed to renounce succession rights to gain Mexico.
Yes, Maximilian was in a bad situation from the start. He then proceeded to make it worse by alienating his allies and choosing his friends poorly. He would probably have been a lousy Austrian emperor. Even though Austria was used to Habsburgs, there was still the issue of nationalism that was hostile to the crown.
My source is Sara Yorke Stevenson as before.
Do you know anything about his time in Austria before Mexico that suggests that things might have turned out differently? (sincere question, not sarcasm).