I'm a little confused on your 1st Property. You called it a Conventional mortgage but those are hard to come by with 20% down and only financing $24k... not to mention the mortgage cost of $415 is absurdly high for that amount. I'm guessing you got a short amortization (10 year?) portfolio loan with a credit union? I'd just urge you to be careful on terminology. Looks like the same questions could be asked about the 2nd property as well.
I'd just be careful on your leverage. Buy, rehab, cash out refi, rinse and repeat is a great way to quickly increase your portfolio but your overall cash flow (assuming 50% expenses) is pretty low. You're -$90 on the 1st property, +$100 on the 2nd, +$30 on the 3rd, and +$85 on the 4th. That's 4 separate risk items generating about $125 cash flow a month. That's pretty lean, have you heard about the $100 a door standard some people look for?
My only other thought is to really understand your exit strategy. I'm a buy and hold forever sort of investor, are you? Homes bought for $17,000 aren't generally going to appreciate well at all, there's a reason they were sold for $17,000. Selling in a hurry will leave you at the mercy of other vulture investors, not many owner occupied types in those areas I'm guessing. Your exit strategies will be limited in my opinion, just be aware of that.