We currently max out our Roth 401k, Roth IRA, and $2k per month into our vanguard taxable account.

It is generally not advised to hold appreciating property such as real estate inside of an S-Corporation.Taking the properties out will be considered a taxable event.

However dependent upon taxable income you could get away with a pretty low tax bill due to favorable capital gains tax rates.Be sure to work with a qualified intermediary and a tax professional to ensure you comply with all 1031 exchange regulations and to be sure you keep basis correct as all a 1031 does is defer your gain.Happy to help run some numbers or do some basic analysis for you if you would like. 

With respect to your 2 questions, 1) when you sell the property, all the depreciation taken (regardless of whether it was used to offset income in the past) is subject to recapture.2) You can reduce your taxable capital gain by subtracting the selling expenses from the sale price.

If you can invest at a higher return than your interest rate, I'd refrain from paying it off so you can continue to reap the tax benefits of deducting mortgage interest from taxable your rental income.

Section 721 of the Internal Revenue code allows an investor to exchange property held for investment or business purposes for shares in a Real Estate Investment Trust (REIT) or an Operating Partnership without triggering a taxable event.Many investors are aware of a 1031 Exchange where an investor must find a replacement property to defer capital gains taxes on the property that was sold.

That would not be a taxable event. 

If you’ve owned it for a few years there a cap on the amount they can increase the taxable value, I believe it’s 15% excluding improvements to the property.

This salary includes both taxable and non-taxable income.The formula for calculating child support payments can vary depending on your state.

Depreciation recapture tax is the taxable amount on deductions you made for property depreciation.