My wife is from a country that does not allow lending or loans to acquire housing.

At another property with just the sidewalk I let the tenants take care of it, but the liability of these steep stairs makes it too important for it to be haphazard or me having to scold them to shovel and salt the walk and steps.I know in snowy areas people with houses contract plowing for the winter at a flat rate.

There isn't enough information in here about the current state of the house to be able to advise you, but I would think #3 is a definite no as it seems unnecessary from a cost perspective although that market has scale to accept it.

What are the odds your house burns down or gets hit with a tornado?  

Find the people who turn dirt into pads, pads into foundations, foundations into hosueses and houses into communities.

Can you suggest an insurance company and contacts for our rental houses?

You may have heard that staging your home properly can make a big difference when you sell your house, but what exactly is home staging, and is it really worth your time and effort?

I wanted to purchase a vacant house adjacent to two of mine years ago and it ended up selling, listed/sold same keystrokes to someone with a connection to the nonprofit for less than what I would have paid. 

And my final dream is to buy land in my home country to build affordable housing for people there.

In most areas in San Diego, that is condos, town houses, etcWith that budget, I would be leery of recommending San Diego.