For such things a Hex-Editor is just perfect
The other change would not be that easy I suppose, at least I don`t have any clue how to solve that without deeper patching or fiddling with source-code (which I don`t think is available)
As workaround you could use Excel as "Season"-Tool and within that you could have the sprint race as non championship race with reduced race length and patched qual-powers so that you get the exact starting grid for the full-race. You can also add extra points for fastest lap and so on.
To make my 1.000th post a little bit more relevant, I will attach the Excel I used for the Championship with my relaunched personal carset (currently not released). With a little bit of editing (F1- Points, 20 races, the sprints and points for fastest lap) you can use it as template for a 2021 season. The primary reason I additionally used the Excel besides the 16 races was Information like (reason out if classified, lap charts, etc.)
I use a virtual XP machine with Office 2003, so this is an xls-File. For security reasons I have also attached the Hash-Value of my version. My version doesn`t include an makros.
SHA-256 HASH of the xls-file:
acaf9af874968e1f4e7be91a36a51b27f6e13c0a54893f84074548e109de995a