files ending with php~ are temp files, when you install a mod it creates a backup of the file before altering it and names it as filename.php~
as for other pages saying 2.0.x instead of 2.0.18
it's not really a big issue
not every single file gets altered during an update
only files that were altered during an update were changed to state 2.0.18
even in a clean fresh install

not every file says 2.0.18
I know it's a bit confusing but nothing really to worry about
if you go to
https://custom.simplemachines.org/upgrades/and click on the name of the update package, not the download but the actual name it will open a parse page to show what all changes were made
you can double check the pages that are failing to make sure the changes were made
when you updated, was there any errors?
also please note, it's customary to wait 24 hours before bumping a topic....