How does a detached garage impact appraised value?

As you mentioned, your cash flow is now impacted. 

No you'll lose the investor permanently if you don't make money on the deal EVEN if he gets paid!

I know analysis paralysis is the biggest hurdle for most wannabe real estate investors, but I also don't want to jump in if it's advised to wait until I set- up a more permanent residence.

My question is how do I address the positive impact paying the principal has.

The owner did this because it is cheaper and easier to add an RV plug than it is to buy a home to fill a lot.If the RV's currently occupying those lots are skirted (or otherwise obviously permanent), then I would treat it exactly like a lot renter in your evaluation.  

HI Dakotah,Its sounds like  from what you've mentioned in your scenario that you wont have very much issues qualifying from an income perspective since you're saving 50%+ of your income and you live in West Hollywood that means your income is probably $$$ more than sufficient since West Hollywood is one of the most expensive areas in CA other than south bay, santa monica, La jolla, rancho santa fe, Newport beach and couple other areas in CA.To figure out how much impact this car will have on your ability to qualify you can use a general gauge that every $100 dollars of car payment will lower your ability to qualify by about 20,000 in loan amount in general.

USAA had two great features (1) online data entry allowed for plug and play changes to coverage terms and recalculation of the impact on the premiums (2) you can adjust the dwelling policy limit (within a range) rather than just getting stuck with some inflated cost estimator.  

However, at any point, something can happen to make them not pay, either temporary, or permanent.

., would be considered capital improvements because they are permanently built-in.