On the cats I would request a professional cleaning of the entire house prior to closing. And honestly that would be only if I fell in love with the house from the curb. More than likely I would walk out the minute I saw cats. Don't hate animals, but I am allergic to cats. It isn't worth the headache. My renters with cats pay an extra $15 a month per cat plus a $250 deposit, since I know I won't be able to go in & clean the house after they move out. Our nicer houses I won't even allow cats at all.
I forgot to report back in the fly bags I bought. They have a pheromone inside the bag, you add water hang the bag up & flies are attracted to it. The bag is working to attract flies well. I still have flies, but I only hung 1 bag up to start with. I will hang more bags this weekend. I ordered the bags online, but actually seen them at Walmart. They are about $5 a bag.