@Michael OldaniI've tracked multiple flip houses in my farm area.

Seed doesn't actually finance the deal, they just open up credit cards for you.

I've read some people are accepting debit or credit cards but this seems risky as well since they can call their bank to dispute the charge.

So I have been mostly using my brokerage account to buy properties as my credit line.  

I am about to start the process of shopping for conventional loan rates and getting pre-approved, but am concerned if I shop too much within a short time period it will adversely affect my credit score.Does every loan inquiry during the shopping process negatively affect your credit or is there a "grace" period after the first inquiry?

@Patrick Philip hire a v.a to keep track of all the calls with a script to go by 

I'm independent, no debt, no student loans, very low tuition (with financial aid grants), rent of $500 per month, credit score above 750 and a small chunk of change saved up in the amount of $15,000. 

Personal loan via credit Union for expenses4.

Another avenue would be to use some of that 150-200k to pay down your mortgage, then take out a line of credit on your home to get started in the Real Estate Investing world.

I like to see a much longer track record ... to each their own.