The answer you will get is that they are expensive and time consuming. 

Very modest homes similar to this one and in this area rent for around $1500-$2000/week in the high season.We've started renovations by tearing out the kitchen and floors, opening up the kitchen and living room to make one large great room. 

All this I’m looking to keep on a modest budget and am willing to do as much of the work myself if needed.

I would assume it would be too time consuming to try to assess more specifically the operating expenses of each particular house?

Many investors (particularly those who are buying) would welcome a return to less of a seller's market, with more inventory and more modest price increases. 

On the downside risk side of things I'd try to ensure that nothing substantial has changed with regards to consumer metrics and preferences. 

Pro tip: take particular care to cover book shelves—removing dust from our books was one of the most time-consuming cleaning jobs we faced. 2.Pack as though you will be travelingThink carefully about everything you will need over the full duration of the renovation (plus the inevitable extension) when packing.

Also, through normal economic cycles—I would think a stock market correction may be naturally occurring in 12-18 months so I can accept a modest returnI only have exterior pictures of the property which shows it as “fine/livable”.

Actively re-starting about 2 1/ years ago in RE investing we began to consume a lot of material on investing (podcasts, books, etc.), the end result being we took our eyes off the ball to the deals that were right in front of us!

Risk and reward is real, I would rather have massive success with a few failures than 0 or a very modest return by window shopping.