Why are the IOP's necessary here?
Why is the IOP in pintarle, arreglarle, etc. necessary in this sentence? It seems that it would make sense without them... (?) What are the "le"'s referring to?
"Bueno, pues podría pintarle las paredes, arreglarle problemas con la tubería, poner pisos, o arreglar su calefacción o aire acondicionado."
Translation: "Well, I could paint the walls, fix plumbing problems, install floors, or fix your heat or air conditioner/conditioning."
In this case, you can say it both ways, with or without "le" after the verb. "Bueno, pues podría pintarle las paredes." = "OK, well I could paint the walls for you." "Bueno, pues podría pintar las paredes" = "OK, well I could paint the walls."
What's an "iop"
All I can think of is that these tasks are able to be done for you, as in a job posting advertising someone's maintenance business. "I could paint the walls for you", etc. Otherwise, Indirect Object Pronouns don't seem correct here.