.$8,000 would likely go away in closing costs.

Purchase price: $90,000 Cash invested: $55,000 Triplex in SE Cleveland (D+ neighborhood)Purchased for 90 and saw 105 for valuation. 25% down plus closing costs and unit repairs has led to about 50-60k going into the deal.

With down payments, improvements, commissions, title work, holding costs etc....

I personally do not prefer to hold high cost SFRs as LTR investments.  

Focus on key areas first (like floors, walls, kitchen, or bathroom), which may help you handle the costs more gradually, even if it means moving in furniture or updating fixtures down the line.Also, since the tenant left it in rough shape, be sure to document all the damage (photos, receipts) in case you decide to pursue reimbursement through their security deposit or in court.

Refinancing has more nuances than it seems, and so do closing costs.

Also, what are some other low cost amenities that I can add to my STR that will yield a higher ROI?

That may increase your cost or limit the coverage you can get.The Year that the following were updated (either partially or fully) would be good to know:- Heating systems- Roof- Plumbing- electricalSome companies will not write properties with systems that have not been updated.As long as you are living there, the proper policy for a 1-4 family is a "Homeowners" policy.

It hurts the tenants ability to find another rental, nobody wins, and it takes forever costing you money. 

Rental income is subject to tax, but it is also possible to deduct many costs related to owning and maintaining rental property, including property management fees, repairs, and mortgage interest payments.Additionally, for those investors holding properties in Germany for the long-term, the country's capital gains tax law is attractive.