Question....what are ways to transfer or get NPC's money, I know one way, but are there better ways?

Are you able to use mods? If you are, then there is a fantastic mod from SimRealist. Actually, it may require two of them: SNB and SNB-Bills. These two enable your Sims to have their own bank accounts. I was able to have my Rock Star pay his Agent via this system. I think your Sim just has to know them. Then you can 'send' money to whomever you need to, and punch in an amount, hit send and off it goes.