Serfdom was abolished in Prussia on 9 October 1807, under King Friedrich Wilhelm III.
Whether Alexander was a patricide is open to question, however, that has no bearing on his attitude to his rule, whether benevolent or not.
Kaiser Franz `kept Napoleon's son away from his father`. Let`s examine that, shall we: he was born on 20 March 1811. N left to invade Russia early in 1812 (`Sorry I missed your birthday, son, there were these other guys I just HAD to conquer`). N did not see much of his son in 1812, 1813, 1814 or 1815. Thereafter he was on St Helena. Dy trips from Austria down to the south Atlantic were not available and I believe an airport on St H is opening about now. I cannot believe that you raise this in order to demonstrate that N`s opponents were tyrants and despots.
The reforms in Prussia in 1807 - 1815 were extensive, radical and very courageous, given the state of the county in 1806.
During that period, Prussian women donated their gold jewellery to support the war effort and received iron jewellery in exchange (`I gave my gold for iron` was their proud claim). Scarcely the actions of the downtrodden to a deeply unpopular despot.
`What did they do to improve the lot of their subjects?` I suggest you read up about Prussia`s reforms 1807 - 1815.
N was so scared of the royalists in southern France 1815, that he made a great detour to avoid them.