This has nothing to do with taxes, but:
so I was thinking of maybe renting and living there using 100% of my mortgaged home as the business.
That would most likely be in direct violation of your mortgage agreement. It would definitely be in 100% violation of your homeowner's insurance policy. If for any reason you had an insurance claim, the insurance company would refuse the payout because the home was not being used for it's insured purpose as your primary residence. So if you have a major loss such as fire, flood, hurricane, tornado, etc., you would "in effect" be uninsured. Then the mortgage lender will foreclose on the property and you lose everything, including the business.
Additionally, if there are zoning laws in your locale and your property isn't zoned for business use, your problems will be further compounded. Please seek legal advice from a professional in your local area - and not just a tax professional either.
