Are we going to see returns that look like stock market numbers for the foreseeable future. 

Partially because you did not rent it for an entire year but mostly because of upfront expenses: getting it ready for rent, buying furniture, electronics, and other furnishings, stocking up on initial supplies, and so on.

I was thinking about an strategy of doing Cash Out Refinicing putting that money in the stock market (distributed in ETF and some "safer" stocks) to get around a 6% anual return (estimating that low because is the "standard" average, however my current stock portafolio has a cummulative return of 66% in the last 4 years).

How low will it go, no one really knows, but I agree with predictions of 20-25%. 

Not always easy to get unless you stock a couple of cords, which takes a lot of space.Propane is going to be your friend up there.

What should be my stock vs real estate vs fixed income ratio?

If you get a B class low risk investment that is predictable, you should be able to refinance is 7-10 years and start your snowball.  

It’s really a wild market and variable options can cause flux in multiple directions like jobs report which you would think have been the opposite either way causes some confusion in predicting perfect storm.As a banker who funds a good number of investment purchases and primary homes each month I have seen a big drop and its over 1% on average in rates since June.

I would hazard a guess that 90% of all investors that ever made any serious money in real estate did it the old fashioned way - they bought the property and held the property, the same way that 90% of all investors that ever made any serious money in the stock market did.

So, your prediction that there would be at least $20k more if everything is included should be accurate.The reason for choosing a JADU is that converting the garage into an ADU would require a separate laundry setup and an additional electrical panel in the main house, which would increase the renovation costs for the main house itself.