I have a non-relative friend that I met online who lives in Romania. I would like for him to come to the US for an extended visit. He will be applying for a tourist visa, but in reading up on the requirements, I am concerned about his prospects for approval. He is young (20's), owns a flat, so he does own real property, but is unmarried, unemployed, and has little financial means. I am a US citizen, willing to pay his expenses for everything - visa, airline ticket, and all of his expenses while he is here in the US. I am also willing to complete an affidavit of support (I significantly exceed the financial requirements) along with a letter of invitation for him to take to the embassy in Bucharest.
My question is what are his odds of getting a visitors visa given the circumstances, and what kind of questions can he be expected to be asked at the embassy? If his odds are low, what can I do to help improve them?