IMO a trust is the way to go. Will probably cost $2500 to $4000 to set up, but prevents your heirs from spending multiples of that on probate fees. I’m a recent beneficiary of an A-B trust. No probate, no estate tax
Every situation is different so you should consult an attorney that specializes in these things before making any rash decisions. Consultations are almost always free. I think by simply putting your kids name on title would be interpreted as a gift and then subject you and/or them to the gift tax.
If you sell the houses before you die (living in them for at least two out of five years before the sale) the accumulated depreciation would reduce the cost basis, but the $250K/$500K exclusion would apply. In your case the accumulated depreciation looks to give you below zero cost basis, so it looks likely you would be above the exclusion limits.
