So it is important to match the "owner/taxpayer". 

Account Closed I would approach the tenants on either side of the vacancy and offer them the space at a substantial discount on a term matching the balance of their current lease.

Instead of sales pitches, give them useful information that matches their interests.

You'll have to put it all together and match it to your deal design.

Do I have to return his security deposit?

It is increasingly common for a PM to charge a "leasing fee" which covers all the costs of marketing, showing, screening, placing tenant under contract, collecting deposit and rent, setting up utilities, getting the tenant placed, etc.If the PM can't justify the cost, then they shouldn't be charging it.

Work to save a lot of cash (Which I just reduced my 401K savings rate to only cover my employer’s full match so that’ll be a couple hundred extra each month and I’m about to fully pay off my car in six months and that’ll be an extra $500/mo.

While separate accounts sure helps with the audit trail, it's not necessary if you note the reason for a a deposit and withdrawal on the drafts or "source" document. 

BUT regardless of that, the numbers should still match your original term sheet!

I would drop your rent rate to match the market and advertise it as unfurnished.