Welcome to the forum!
HQ, SQ, cider, curry, Stranger Things... what a day, indeed!
In regards to your question: if you have fun painting, then paint! I can see in the pictures that you do know someone who knows how to paint, maybe it was yourself.
And that's a solid standard right there, too. Tips and threads around the topic of mini painting are to be found all around here.
Don't leave components of your favorite game in a clean corner just because you fear it's gonna lose value. A figure in a sprue is not a figure but literally a useless piece of plastic.
Treat the game well while playing and you're fine. Don't serve crisps (as the British say) with sticky dips while playing and you're fine.
I don't think figures in sprues make a difference in value if the game as a whole isn't still shrinkwrapped, which would make the point invalid.
And a shrinkwrapped game in the cupboard of a middleaged

is a wasted game.
Have some

and a

and fumble through the darkness and depth of these forums.