Your adjusted basis is original basis + expense of sale (includes staging but also other costs) − depreciation allowed or allowable + capital improvements. You can see this on Form 4797, Part III; rental property is most likely section 1250. In your example, it'd be $1.06 million minus depreciation (hopefully you took depreciation on the furnace and water heater after they were placed in service as well).
So for a capital improvement that has been fully depreciated, the depreciation recapture and the cost of the improvement will cancel out, and there will be no net effect on the adjusted basis. For a capital improvement that was put into service immediately before the sale, there is no depreciation, and the whole amount is added to your basis. For you it's in between; the net amount that was not depreciated is added to your basis.
You'll pay depreciation recapture on the depreciation allowed or allowable; it's taxed like regular income up to a maximum rate of 25%. The rest should be long-term capital gains. The only other cost you mentioned is repairs, which presumably you've already deducted on Schedule E, and if you haven't been able to take the full deduction you should be able to this year.