The bar for extraordinary abilities is high. Read up on visa guidelines, consult with some immigration lawyers to see if you stand a chance.
Founding a company doesn't open any extra immigration paths as far as I know. Except for EB-5 - theoretically you could invest those $900k+ into your new company, but there are rules to follow, beware. Your investment needs to create 10 full time jobs for americans and in California in tech you'd likely need way more than $900k for that.
Community property refers to property and assets acquired during the marriage. Italy has almost the exact same concept in marriage/divorce law, called matrimonial property. Community property is split equally if the couple divorces, though many exceptions and possible lawsuits apply, and couples can sign a prenuptial agreement before marrying.
Founding a company doesn't open any extra immigration paths as far as I know. Except for EB-5 - theoretically you could invest those $900k+ into your new company, but there are rules to follow, beware. Your investment needs to create 10 full time jobs for americans and in California in tech you'd likely need way more than $900k for that.