I can remember being upside on my own mortgage merely 3 or 4 years ago.  

Do you merely look at the purchase price, ARV and potential rent (also considering other expenses)? 

It's costly, time consuming, stressful and ends up being a lose-lose proposition.Review the terms of the current lease/rental agreement and see what it says about "occupancy" and "guests" and see how you can achieve your goal with merely enforcing the terms of the rental agreement.

If I give someone a price it not merely a point of negotiation.

In any case, I strongly suggest you hire a PA to handle your claim so they can help you understand your rights as the policy holder, what's covered and what's not.

I'm also looking at building Accessory Dwelling Units, but am thinking of starting with mere garage conversions...this approach seems to be more cheap and simple.

They are not a scam, they are merely a niche product offering with a high level of risk.

My capital (if I'm talking about from my own pocket) is a mere $3000-$4000.

-I currently work full-time and my annual savings is ~$10K.My goal in getting into real estate is to merely replace my income so that I can live off passive income and quit my job.

I've heard that though it does "lower" your credit score it is merely by 1 point.