It now cash flows beautifully, which I continue to utilize for other my other properties. 

They need to do all their due diligence including understanding the value that will be added by the ADU, the finance options available, the consequences of adding the ADU (rent control, property taxes, rental limitations, etc), etc.Good luck As with all things, it depends on the investor and the equity.If they are able to leverage existing equity to buy it under a HEL or HELOC, then they are adding equity with no out of pocket expenses, and adding immediate and longterm cashflow to existing stock.We like ADU's because there isn't more land being created in our city that is landlocked...but there is more density available to those with large lot under-utilized sfh.In my market, it typically costs $2 to add less than $1 of value on single build ADUs.  

We want to travel and invest and are considering converting this short term rental to a long term rental to avoid sales tax, paying utilities and general management of the property. 

I pay no utilities and these are all one year leases.2) THEIR CREDIT RATINGCollege students almost always pay their rent.

Most investor utilize short term hard money debt to scale their flipping operations where the lender will fund 80+% of the purchase price and the rehab budget which can allow investors to work on multiple projects at once.

If we made a mistake it was not utilizing our mentor even more.Deal analysis is something like this:Deal 1  sold this week at auction for a loss, probably a $4,500 loss, this is in my profit calculation.Deal 2 Bought for 20k sold for 45 with 10k down and 35k financed for 8 years at 8%  I counted this as a 45k asset but probably should have only counted it as 35 since the 10k has been reinvested and is reflected in other assets.Deal 3, bought for 10k and foreclosed on a non performing borrower, we will be all in for under 20k, and should sell for @ 45k, maybe more if we do owner financing.  

Utilize a 1031 Exchange: Under IRS Code Section 1031, you can defer capital gains taxes by reinvesting the proceeds from the sale into a similar “like-kind” property.

If your credit is decent then I would utilize your cash as leverage to leverage:1.

Trying to manage a $1M Airbnb rental while it sounds good you got $6500 in bookings you still have significant costs to operate it with maintenance repairs, utilities etc.

If you're planning on utilizing a self-showing model with cameras you'll need to make sure you disclose to prospective tenants viewing the property that there are cameras on premise.At scale, we've coordinated 160,000+ on-demand/self showings with smart lockboxes over the past 5 almost 6 years with very few issues.