Guryon
Okay here my suggestions. 1 have the leaky caldron and Diagon Alley renovated easy to get the purebloods behind it by saying it would be embarrassing if a wizard from another country came and looked down on them because have dirty and Poor looks. 2 culture and etiquette Center again easy to get the purebloods behind it say it well limit or stop muggle influence in their world. 3 magic technology of course is another one especially if he's writing stories a illusion TV that acts like 3D holographic TV would be cool as well as other magic items at replicate or improve technology. This 1 is just my opinion and more of a warning but I'm hoping you do not follow Canon too much mostly because you have at least four extra people in your story and a changed Harry Potter you have two parents who are alive one girl who never was born and a mc with crazy magic powers even an average Joe can knock canon off course just by existing let alone all them. It's just not reasonable and feasible in my opinion unless the main character goes out of his way to keep cannon on course which is usually a bad idea for story's(make them seem to forced). I would say in my option after the first year maybe third would be the maximum for Canon events without it going out the window. If you like any of my suggestions and need clarification or more information on them just let me know.
creating animated comics for the wizarding world can be interesting. the history of the wizarding world is interesting and rich and can be easily translated into history or comics. (discovery of the new world, the founding of hogwarts, ilvermorny, Ekrizdis and Azkaban, the wizarding wars, the wars with the goblins.) It's a good year to develop a literature business in addition, Professor Gilderoy Lockhart had to have the help of an unscrupulous company to help him publish his "stories" as well as obtain his order of merlin, enough to remplace the opposate company at the end of the year and take its place. (a company probably belonging to the dark faction). at the same time prodire, a newspaper where helping to finance the development of the "Quibbler" can be interesting, the "Daily-prophet" is the only daily newspaper in England.