I couldn't agree more with @Matt Hurley, when the market does correct, getting financing will become more difficult.

Great to see you take that first and maybe most difficult step in real estate investment: reaching out on BiggerPockets.

It’s a lot of work and it’s been an interesting experience balancing a growing flipping business and growing a brokerage.

But the remaining balance would still be less Out of Pocket than closing costs on a conventional mortgage. 

When dealing with a loan modification.....make sure you know the Real balance....not the balance they are making payments, as typically about 1/3 is “set aside” until the end/pay off....sometimes known as a “silent second”.

With $300k of student debt hanging over your head simply qualifying to buy additional investment properties will be extremely difficult cause your debt ratios will be totally blown out. 

In general, are there restriction on using SDIRA on a development/construction project...we have a first lien balance around $80k and reno should be $250k.

PS one of my very short stints was attempting to sell dental equipment door to door.. you know high speed drills low speed and delivery systems and chairs and lights etc.. sit down dentistry was just starting to take off.. turned out Dentist before that had a huge problem with back aches.I worked with a start up called healthkit.. they had a delivery system way ahead of its time.. it was all numatic and was used in the military because the holder of the drills was solid aluminum block 2 X 2 X 6  with no moving parts.. unlike in those days the ones that looked like something out of a sci fi movie and would break all the time.. but of course ours was the most expensive and well .. being that and being the industry was very difficult to sell.

Are there any tips/tricks to get into real estate with high loan balances and credit card debt?

Multiple times, the CPA can produce a short 1-page Income Statement or Balance Sheet, but in reality, if you want details, it's more than a page long.