For your sake since I have no idea what other thread is being referred to....
The first post: you need to set up contracts. Everything that automatically buys, will automatically buy from the world market unless you set up the contracts yourself. However, it MUST be stressed that there is nothing wrong with buying from the world market. You can set the desired quality to the minimum when buying for your enterprise and corps and sell your high quality goods to others, increasing your potential revenue.
Anyway, from the top menu, "Corporations >> Contracts >> Product Contracts Setup" will let you set up contracts between your corporations and country.
For the second post, there are four main things that could be causing you to have unemployed workers in a category that has more than 0 workers needed for 100%. First, you had 0 workers in some category at the beginning of the month. If there is a shortage in one category, corporations will proportionally fire all other workers. Second, someone relocated a corporation to your country. The corporation starts at 0% hiring and only rises 15% per month after that. Third, you recently fixed the first problem mentioned. A corporation that goes down in hiring takes time to get up. Fourth, someone has reduced hiring below 100% in a private (or more specifically enterprise public corporation) for the purpose of tanking the market value.