@Stacey Schwartz As Linda said, you don't want to do this incorrectly and end up paying a penalty or go through an audit done later. 

Property Taxes - research when property taxes are due at the City, County, and school levels.Some taxes are due all at once or some have installment payments.Each City/County/School is different.Income taxes are due with the filing of your individual return.However, you may be required to pay income taxes on a quarterly period to avoid penalties.

But to help protect yourself as a landlord and prevent these issues from happening, I would set up the tenancy agreement to have the tenant pay security deposit within 2 business days of signing to make the lease valid. 1st month rent must be received in full prior to occupancy or no keys are given and the lease will be voided along with a liquidated damage penalty of 1 month (where you could keep the deposit and if they wanted to challenge you on it then you could countersue in court for the full month penalty).

When asked about the minors being alone, they felt there was nothing wrong with the situation.I am considering informing them that the lease will not be renewed, waiving all penalties for an early lease termination, and offering them a cash incentive to leave early on a sliding scale with the highest offer for ASAP.Any thoughts?

If someone is injured or worse, you would likely not just be looking at civil penalties, but I would think they would come after you criminally.

But by going off market, hopefully a seller wont ask for that.Also, during the inspection period, you can back out the contract for any reason without penalty.

Neither are the penalties: http://massrealestatelawblog.com/2013/03/16/boston...

For unit 2, if they were under a lease and left early, then they will have to pay a penalty for breaking the lease. 

Hi @Ray Os, my understanding of case law (not statutory, nothing is currently codified as far as I'm aware) is that the maximum "enforceable" penalty for a residential lease break in Colorado is the equivalent of two months' rent. 

What are the prepayment penalties?