1. Yes he can petition you now, he won;t need to show financials until the interview in 5-6 months, and he will have several paystubs by then and can bring a letter from the employer saying his job is stable and long term too. He would need to keep the job at the very least until you are approved for a greencard after AOS, so that can be a year or more after you file.
2/3. He can try and find a co-sponsor, a friend or family member to stand financial guarantoor for you.
One thing- you say you met more than 2 years ago. Have you physically met DURING the last two years? That is a requirement for filing for a K1.
