Being tax efficient is very important. 

And keep in mind this is in addition to your normal tax liability.

Having installed my own 14kw solar panel system on my own house without prior experience, I decided to do it myself on weekends and before and after work.It was way steeper than my roof.

Let’s say we pay X amount in mortgage.My question is : how do I calculate mortgage/interest/property tax for other house which we have rented so that I can deduct that from rental income?

Prior to that I had never been late on a payment.  

If you want to completely defer all tax  then of course you'll need to line up the 1031 and complete it with the purchase of that property you'll then use for investment (with some personal use) prior to moving in and converting it to your primary.But the other way would be to start a 1031 exchagne in one year in such a way that it's 180 period crosses over into the next year. 

Yes, they are. separate meters and property tax bills.  

We both work remotely and are curious about how long we can stay at the rental before it becomes an issue, wether thats state tax implications or perhaps when our jobs should be notified that were working in WA vs OR?

But between my broker fee and the lenders fees, it's usually 2-3% of the loan amount.They're ignoring the $7k escrow for taxes and insurance, for example.

If for example a home is selling for $225,000 it will have an estimate of $1,462/month.With 25% down the calculator shows: $1,023 per month Principal and interest $806Property taxes$125Homeowners insurance$92How can I get a better idea of the total including everything?