Regardless how how much work an OOS takes on in their first project (full BRRRR or just paint & carpet) the next one they buy usually needs less work than the previous one.

And even in areas with no fire damage, you'll almost certainly need to replace the carpet, Kilz and paint the walls as the smoke smell won't come out otherwise. 

And like @Dan M. said, painting will come later - should be last thing actually.

You can build up goodwill sending grocery cards at Christmas, having a mini fridge to rush over the moment there is a problem, giving rent credits, etc. and it will mean LESS THAN ZERO as soon as you have a late fee you expect them to pay, a pet that you cannot approve, anytime the rent goes up, telling them they can't paint the walls and ceiling the color they want... then you are the scumbag landlord.

And for someone to get so much of the fruits of my labor seems like an injustice to myself. does that help paint the picture a bit better? 

Always, get the paint updated to a relevant color and then take first class photos.

THATS how you add the value, by repairing the defects, kicking out squatters, painting over spraypaint etc.

Interior and Exterior Upgrades; Modern Appliances, Tiling, paint, etc...What was the outcome?

. : $2,347-Paint, all new doors, plumbing fixtures, drywall work, garbage disposal, carpet, bathtub: $3,934-Labor: $7,976The previous owner did not do any updates to this unit for the last 25 years!

We did a light rehab which included paint, carpet, fixtures, turf in the backyard, and a new roof.