I also leave a “welcome basket” containing about $20 worth of goodies including dark chocolate, good ground coffee, a bag of popcorn and 2 bottles of water.

Big refill bottles for a buck.

I'd leave a candy bar and small bottle of wine on each pillow. 

Bottles of water, whatever prepackaged stuff I can supply, sun chips, whatever.What kinds of liabilities should I be concerned with when I'm selling/giving away food in my Airbnb?

Things like coffee, tea, bottled water (our tap water is really hard and tastes gross), as well as items like toilet paper, shampoo, conditioner, hand soap, dish soap, etc. 

I looked into the bottled “spring water” option.

Additionally there was a empty orange juice gallon bottle container outside of the condo unit used to water the plants outside and they just left it in the picture whereas I would’ve moved it out.

A teaspoon of this is a normal size squirt bottle filled with water (please no windex bottles or the like that contained ammonia.)

"Is there any reason why you can’t go to Hone Depot, get a bottle of Ortho Home Defense and spray the house?"

Jay, I'll send you a bottle of local pinot if you find and reply to this thread today.