Last year one of our lenders would not lend to new customers or customers who have never did a commercial loan with them.  

For "Foreign Borrowers" your loans are very limited. 

what if the seller has existing loans and liens?

What other kinds of loans or financing strategies are available that don't involve using too much of your own cash?

Is this using a 20% down, conventional or DSCR loan, although I would think a first time investor would use a conventional loan.

Do you have a significant other who could take out the loan?

We are in Los Angeles, and although we do not own anything in SD, we hold a loan on a portfolio of SFR's there that is not performing at the moment.

Your answer needs to make sense, and be true.Also refi'ing your current primary into an investment loan also has the potential to be fraudulent if your family still occupies it as their primary. 

I want to purchase an investment condo for $150,000.I want to get Heloc loan from my other investment condo for $50,000 and use it as downtown payment for this condo.Can I get a 30 year fixed conventional loan for $100,000 and use $50,000 for down payment from heloc?

typically no special license is needed when doing it for hard money loans that I am aware of. there may be states like california and nevada that are tricky where lenders need a license of some sort but for most part brokers i have seen are not licensed. 14 or 15 states require state license and NMLS registration.