Abolish freedom, albeit without much of a limit. Just enough to make people not free to be stupid and indirectly weaken society with awful personal judgement. Also increase spending for research grants in stem fields and education. Removing all culture based laws as well would definitely be important. The less things controlled by feelings and believes of good, rather than a good measured by increased productivity and output is worthless, so if it doesn't make people more content with their own lives or work more efficiently, it's gone.
Encouraging large segments of the population in places like Pakistan and China to move elsewhere in the Western world and vice versa, to start destroying cultural/tribal barriers in the species and try to mesh all the subdivisions into a cohesive, unified whole, would definitely be a long term project. I'd definitely be tempted to nuke Jerusalem, just because it is a bastion of conflict and division, and a cornerstone in some of the worst diseases of the mind, that mankind still struggle with, though with unilateral, unopposed authority, I guess it'd be unnecessary.
Abolishing suburban neighbourhoods would be an important project too. It's waaayyy overdue to condense our land consumption, and lawns are an awful waste of water in many countries.
Nuclear power everywhere that isn't too rich in tectonic or volcanic activity. Definitely remove the plants in blatantly stupid locations, like Cascadia.
Develop AI and assign one to every human being, because a lot of cultures like to raise people with extremely untrustworthy dispositions and recklessly selfish tendencies, which corrode every life around them like clouds of azeotropic sulfuric acid. Definitely can't have them going around without a leash.