Assessed value is currently $450,000 and when its completed I predict it to be valued at roughly 1.5 to 2 million dollars. 

We cant predict the future but I would never think it is wise to lose $1000 per month unless you are %100 sure the appreciation will outweigh the loss.

I think trying to predict a downturn from any one subset of data points (in this case anecdotal evidence from mortgage lenders) is not going to give you an accurate idea.  

If the stock market corrects 20% as some predict  then we will see a price decline in the central valley.

A sound person is not always predictable but we are playing a game of odds.Frank

I could also just sell it, and pay the tax, given some of the dire economic predictions under Trumps administration.I am leaning toward 1031 exchange, but not sure if this is the best option, any advice is greatly appreciated.  

., a lot of those points are subjective, and also hard to predict.

However, the occasional backed toilet, or dead light bulb (etc.) is not as predictable.

For that as a quick comfort level I like 3 months of rent saved, but I do a detailed calc looking at building a fund for predicted replacements of things like roof, furnace, any other item over $500.

Many do not predict another 07-08 collapse as that was the perfect storm of several causes.