What is the best way to establish a rate to charge security deposit for repairs such as drywall patching and repainting if I do the work myself.

Once you establish the market rent start digging into the expenses.Is there alot of vacancy?

But I want to establish relationships with buyers and then find the properties for them based on their criteria.

I'd also say until you are well established in an area and have a great team to work with you should not be buying anything without seeing it personally.  

And when you are starting off, you should try to establish trust and relationship with your buyers first.

I am now seeking a way to establish a credit facility (200K to 1M) to help me scale up faster.

Then look at your investment requirements and you can establish an offer.

What are some strategies that have been successful for you here beginning a career in sales, approaching and successfully working with investors, and establishing long term win-win relationships?

It would depend on how the upside is structured, but it feels like the lack of history is siginificant as it introduces more risk.What is a common rate for established investors in your area?  

The guru's will like to tell you otherwise, but for the most part the kind of people I see that get started investing in real estate and have success tend to be people that either have a career established or they have a house with some equity.