Doesn't it negatively impact my credit score every time I ask a different bank if they can prequalify me?

Look at J Martin's threads and see how he went from negative net worth to owning $1M+ of real estate in Richmond and Oakland in a few short years.

However, it will negatively impact how much money you can borrow since it will increase your DTI ratio.  

One negative issue with this strategy is you have to keep looking all the time to grow your portfolio esp if you want to find them at a deep discount vs with larger multifamily you get a lot if doors at once

Most investors ignore the value of equity and as a result are actually unknowingly experiencing negative cash flow.

I found plenty of negative.  

Are there some negative lending laws against HML there ?

Is there any way of removing negative items on your credit report before they expire off.

It's a negative I've come across often but I haven't seen an example of how it could negatively impact me.  

While our real estate market in Houston is not the disaster that many predicted with the Oil and Gas slowdown, lots of statistics point to a slowdown in real estate.