Hey there! So, bearing in mind that this is a triplex, some things to consider:
1) You have a 10% Cash on Cash return, which is (+/- 1-2%) pretty close to a total US stock market averaged annualized return. That being the case, you have to ask yourself whether it's worth taking on the additional risk or a real estate investment is worth it to get the same, or close to the same, return.
2) You have three sets of mechanicals (hot water heaters, electrical panels, furnaces, etc) to maintain, meaning your long term capital costs are going to be higher than with a SFH or a duplex. Based on this, the maintenance numbers you're getting may actually be high average long term numbers for the property. Maybe the seller would be willing to provide a Schedule E for a few more years to see.
3) I know you said that you are going to do tenant placement for the first few years, but it might be worth at least seeing how tenant placement fees affect your budget in the event that an unexpected move, serious injury, or whatever causes you to rely more on property management.
When I adjust your numbers to show you paying 1.5 lease renewals and 1.5 tenant placements per year (roughly in line with a 2 year tenant stay assumption), your monthly cashflow drops to around 8%. To me, this property is kind of in the "danger zone." It could be ok to decent, and it could also get bad, quick, if you accrue a lot of capital expenses (or develop a nasty water leak, or whatever) in the first couple of years.
As jnc mentions, a 50K (or even sub 50k) loan is definitely doable. I have two right now that were under 50K at close. and one just over it.
Water has proven to be a disappointment to be in one of my duplexes over the past year. Tenants have no incentive to limit their use without some financial consequence. I'm actually moving to submetering my utilities, dropping rents, and making tenants responsible for the water bill. Every landlord in the area where I'm focusing right now seems to be trying to take some sort of step to make the tenant preserve water, whether it's agreeing to pay up to a certain value per quarter (in which case good luck proving that it's a single tenant's fault with only one meter), submetering, or whatever. Something to consider, whether it's in this property or the next.