I think that's doable as Redfin sends me an estimate every week in email, it seems
That has nothing to do with your cost basis. Once your original cost basis is established, it never changes. But wihen converting back and forth between rental and personal use, the cost bsais is adjusted for depreciation purposes only, each time you convert it back to a rental.
when I sell, if profit is10%.... do I owe cap gains and deprecation on the full 10% or taking the 10% and reducing it by the % of days rented
Unless you qualify for the "2 of last 5" capital gains tax exclusion, you pay taxes on the gain. Percentages of anything really don't matter. But your recaptured depreciation will be taxed anywhere from 0% to a maximum cap of 25% no patter what.
