If you live in it, depending on your tax position these carrying costs may or may not be deductible.  

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?

Understanding the different policies and your risk exposure is properly the most important thing to understand.Understand your deductibles and what is covered with your specific policy (i.e, is sewer back up included, flooding)You can always get an umbrella policy if you want some additional insurance.

Can i take all the income / deductions / as well depreciation on my return ?

Maybe a tax pro could help you navigate this mess and find any possible deductions or offsets.

An employee stole from us last year, and it was covered with no deductible.

What other kind of income can I deduct with Rental Real Estate losses?

Here's what I've been doing: I'm allocating 100% of the mortgage interest and half of the property tax as deductible.

Don't forget Capex deductions come after NOI to create BTCF.

Have a claim damage estimate before filing the claim that is well above your deductible amount 2.