There are hours of answers in here on the forums, and I don't have the time to repeat and retype everything that has been already posted here by many, many others who are more knowledgable than I am. You want free information - that's great! But time doesn't make it free. Your time, or mine. I've told you where to find the answers. You're going to need to dig through the site.

 To answer YOUR specific questions:

1. MLS Realtor, good idea or not?

It depends!
How much will it cost you?
How sweet of a deal did you give the Realtor to sell your deals?

If you cut their rates too much to save your own money, they will NOT be motivated to move your properties over other listings where they get full commisions. Get the idea? You need to make it worth the Realtor's, the Buyer's, and your time if you want to move these deals quickly. You may need to offer the Realtor an extra point if you really want to move these deals.

My suggestions?

Build the realtionships with those professionals you will need along the way to make YOU successful. If you treat people like crap in this business, be careful. Word travels fast and everyone knows everybody. Treat people fair, honest, and polite. You catch more bears with honey than vinegar.

Do investors want deals that are not really officially listed?

Again, it depends!
"Investors" want good deals whather they are listed or not. You have the same chances of finding a motivated seller whether the deal is listed or not. I know, some folks try to go the cheapo route, not use the Realtor to save that fee. That's okay if you know what you are doing and have done LOTS of deals. For the newbie, consider your Realtor to be one of your mentors. You will learn from their experience and knowledge BEFORE you make a costly mistake. There are good and bad Realtors. It's up to you to build your team with people you trust.

Getting back to your marketing list. Did I mention to search the forums yet? There are multiple posts out there already that address marketing and offer more than the four you are focusing on. Three of them are online only marketing. Here you are making the assumption that people will visit your site, reply to your emails, and visit your blogs and social media sites. You NEED to find motivated SELLERS and build your BUYERS list. I know it will take your valuable time to seek out the answers from those who have "been there and done that" before you.

But it beats the heck out of reinventing the wheel. I'm not worried about the other stuff I mentioned, but you might want to be to put your best foot forward when you meet someone for the first time. This game is ALL about relationships.

Have FUN!!!

First tip

1. Use spell check on your marketing and blog posts from now own
2. Check out the forums, this question has been answered many many times
3. Direct mail yellow letters to sellers, it works great
4. Did I mention to check out the forums in this site for previous posts yet?
5. Have fun doing it.