Hopefully you have a decent deposit to offset some damage.  

Once you do that and get a tax ID you can get bank accounts in just the company name (if you ask for it the bank will default to your name dba company name) for security deposit refunds, business expenses etc.To anonymize the ownership of the properties consider living trusts.

Right now I have my direct deposit going into a Bills account, from which I pay off my credit card every month and pay my primary mortgage and all fixed expenses like utilities.

Also, if you win the auction and can't fund by 4pm you lose your deposit.

If after you do your due dilegence like everyone has mentioned above and everything checks out clear, I would either partner with someone who has the cash, use a HML (as mentioned above), ask if she'll do owner financing or if you have some cash at all maybe give her a non refundable deposit to buy you some more time to come up with the funds.

That will be your competition so I'd call around and see what new 2bdrms are going for in that area. 2011-2014 I paid  $1300-$1450 (rent went up over 3 year period) for a brand new 2 story, 2 bdrm loft and had a gym. pool, business center, etc - those bldgs also offer low deposits/move-in incentives since competition is high for good tenants.  

My question is, do I charge the previous tenant for the work and take it out of their deposit?

I have found did you have $20k to deposit you can find a small bank or commercial lender that will loan you the rest of the money.

Tell them I report everything so cash won't help me and will only invite burglars.As to the business name not filed, it's OK, except you just can't deposit checks made to the fictitious name.

If you think he will be a problem, perhaps you can require an increased security deposit (check with local laws to see what is allowed).