No personal story , makes you seem desperate, stick to the facts that you have money and you can pay x amount of dollars and ready to proceed with purchase if offer accepted!

You have to subtract the original $230k you paid out of pocket first...which leaves you with $715k.Now, subtract all the lost income (now negative CF) from the months that you had vacancies, Maint. costs, CAPEX, etc...assuming 15% of rent per year, that's about $15k x 15 years = $180k...which leaves you with $535k in virtual profit.IF we just stopped there, you would have gotten $35k/year return (on average).Now, comes the big money losses.You will be operating at an average loss (and this is real money due to cash out of pocket to pay for expenses not covered from rent due to now negative cash flow)  per year of at least $15k.If you had invested those losses (and since the source would have been liquid this is not a virtual thing) at a measly 5% per year, and reinvested it all every year, you'd be at almost $800k in actual real money.Anytime you accept hard cash losses, you are losing the benefit of your cash being a "verb" instead of a "noun"...and you lose all the compounded profit from you cash being reinvested and in action...forward action.

Re: off season, I use the old tried-and-true of lowering your price :p  I typically set mine at/near the lowest I'm willing to accept and take what I get (I don't go too low because after a certain point the risk/reward doesn't pay off).  

You are not obligated to accept rent.

Enforce late fees and always proceed immediately to eviction when clock ticks down.A tenants personal life issues are not your concern, working with tenants problems 9 time in 10 will only cost you more lost income, landlords are not social workers or family, you need to take all emotions out of your business.

The first month, I tried to have them use Venmo, but they couldn’t figure it out, so I had to drive out to the property and accept cash.

The last time I needed a tenant nothing worked accept a cattle call.

So far I have found 3 properties that I think I would have a fair chance of getting offers accepted on.

This would allow you to better understand what you find acceptable while running your RE business. 

I am wondering at what time period the COC is measured and if the initial COC is below 10% but grows to 15% or 20% or more within 3-5 years is that an acceptable return for a buy and hold investor?