"I didn't take depreciation some years (bad idea)." see a tax pro. the tax laws require you to recapture the depreciation you should have taken while it was a rental even if you didn't actually take the deduction.
yo can not just ignore this nor take the deduction in the year of sale without filing form 3115. and TT can be problemsome to work with when there is on again off again depreciation. it just was not designed for this.
