An idiot who inherited money is powerful but he has a very high possibility of ending up a poor man without knowledge because he'll not be able to secure the money for a very long time unless he's got someone else with the required knowledge regulating and restricting him.
I know people who really inherited billions in my country but ended up poor because of mismanagement of their inherited fortune. Money is power, but when combined with knowledge, you become even more powerful..
When it comes to friends keeping, a rich idiot may not keep knowledgeable friends of his caliber since he'll be useless to them but only leches who milks him dry. Buh a rich and knowledgeable guy would be very powerful and be able to network with people of like mind and affluence which creates more opportunities for him to expand his wealth and affluence.
I agree with every word you said. Money is a very powerful thing, and anyone who has an excess of money can almost acquire anything in this world, but they can't buy knowledge with that money, which is one of the most important things for one to have, because as you said, if someone has money but no brains or knowledge, they will never be able to use that money in the right way, they wouldn't know how they can increase the wealth they have, because they know nothing about businesses and investments, and how they can start and operate them successfully, they will be totally reliant on others, which is not good because people will always take advantage of those who are naive and less knowledgeable.
This is why people who have money but are naive and have no knowledge usually end up losing whatever they have eventually, because they won't understand anything themselves, and people around them will surely keep taking advantage of them, keep taking or stealing money from them until they are finished, and people will also make plans to steal everything from such people in evil ways because they know the person won't even know what's happening.