I went down yesterday to ring their bell (it's second floor of a multi-family) and no answer.Should I be concerned?

The issue was the underlying zoning had changed to commercial over the years and the concern was that the property couldn't be rebuilt if destroyed....I only use that as an example to say that asking what the issue is the best way to get your answer.

With a first walk through I'm more concerned with risks than benefits of adding rooms/baths, etc, because I'm looking for buy and holds not short term flips.Biggies (for me, other people will have different lists): foundation issues, roof issues (look at the roof itself and any signs of water damage on ceilings and walls), mold (beyond a little where things need fixing), leaks in showers that are hard to get at, squishy subfloors around toilets and tubs, termites, knob-and-tube wiring, ungrounded, two-prong outlets, no central HVAC (this is all about your location, some places this is fine), and to a lesser extent water heaters.Heavy duty foundation or mold issues I would pass up, the rest I would consider in my offer price. 

However, I am concerned about our financing. 

As far as investing is concerned as long as a property meets my goals and the numbers work, I'm buying.

One of the main concerns the seller has is how to guarantee that I will maintain the property.

So I should be most concerned about how I’m using the agents time, and displacing any current tenants.And trust me I won’t be advocating for breaking into vacant houses on your behalf!

Ours is in an area that is primarily summer only but with continuous improvements and a good rental manager our utilization is increasing into spring and fall.Best part about vacation Rentals, no concerns about evictions.Worst part, extremely hard to cash flow with traditional LTV rates.

The language in the grandfather clause was vague, which was concerning to those who were against the ordinance and had homes that would be affected.I have no legal background, which is why I have come here (obviously). 

If you come in lower than that, I would not only be concerned about your plan to fill the vacant lots, but also about the overall viability to keep the park occupied and push rents.