>>4First of all, thats not Tor works at all and you didn't read the article. Tor exit node can not alter data that is being sent them because of the many checks through the Tor network as well as the exit node isn't have any idea what that data is.
Also your data is always sent through a 3rd party service all the time. Normally your data does through a ISP routering service to your destination. Honestly you should a run traceroute on a random website and look at all the hops it as to go through.
Secondly in the article you linked, it was not the data people were sending through the node, it was the binares people were downloading from that Tor node that wasn't over TLS. Thats not a service's fault, that the users fault.
Third of all , your dim look on free software baffles me. The Tor network is a not profit organization with no monetary goals thus there is "products" to be made or sold. The only part of your post that made any sense of not using open proxies having they don't have the safely of the Tor network and will be used in a harmful manner.