Any suggestions on a keeping house flies away from home i.e. siding and windows which are cluttered with their crap stains? There is a farm nearby, but everything in the immediate vicinity is clean in and around home. Is there a spray of somesort that I could safely put on the vinyl siding to rid of these pests?

You could wipe the windows with the same kinds of turtlewax, armorall, etc. cleaners that you use for your car. I don't recommend that for the siding because the wax could affect it's fire retardant properties.
You could try washing down the siding with washing soda and water. Washing soda cleans without making a lot of suds, and it is similar to baking soda or salt in that the insects will get the residue on their feet and it dehydrates and kills them (just like those boric acid ant powders work.)

Thanks for the input! I did pick up a pressure washer to try and clean most of the siding. Unfortunately for my front door, right underneath the glass, the stains are so bad I will have to sand and repaint as best as I can because the white is now black.

I haven't heard or am familiar with washing soda, where would I get that?

It's in the laundry detergents aisle in the grocery store.