@Jason Belovich Wow, this is awesome! I love a new investor who loves data !
As for your options, I think you've already pointed out that the Local (4) more DIY investment doesn't really fit your goals or needs, though I always appreciate when new investors do the work of hashing out their options. I'm not an expert in your market, of course, but if your primary goal is to focus on passive income, I think you'd be better served by some of your other options. I know you used estimates, but at $200 net flow per door on Option 4, you could do just as well or better with Option 1 (leveraged turnkey purchases) with a lot less work.
You've already noted your chosen growth strategy (the snowball) and that is almost always my recommended strat for folks who don't need the income right away - it actually can be a huge surprise to folks when you run the long-term numbers for them showing how quickly loans start falling away. Of course, the snowball gets rolling much faster when you're able to purchase a small portfolio right off the bat, but that's just not feasible for a lot of folks. Sounds like you have the right idea about turning your cash flow into accelerated paydown, but also a realistic idea of how long it will take you to get the ball really rolling given your savings potential.
I would say, however, that you could likely do better than the $150 you estimated. Of course, it depends on the market, the provider, the specific props, but I think you cold bump that up to $200 pretty safely if you stick to solid B/B+ props in secondary/tertiary markets (which won't fee any upcoming downturn quite as badly as primaries like SF and seattle).
I would also note that you can get solid investment props for less than $150k in several markets (shout out to Birmingham ;). I like that you're focusing on higher-end props and not trying to stretch your cash into as many doors as possible by looking at cheapies in the C/D range. Stick to B/B+ (A props are good for appreciation but the PITI almost always destroys any potential cash flow) in secondary and tertiary markets. In Birmingham, for example, you can get a solid B+ prop for $120-130k, renting for $1200+, $275 net flow per month with a 30-year loan. B-class (still in solid rental areas with high rental demand) props can be less than $100k (Avgs: B-, $80k B $100k, B+ $120k+). Naturally, Birmingham is my home market so i'm biased, but the South and Midwest have several solid markets where you can find similar figures. Point being, you can get $200+ per door in net flow with a smaller investment.
I would recommend talking to a few different operators in markets you like and getting some solid raw data. Find the average values, rents, returns you can expect for reasonably comparable properties and plug those 'educated estimates' into your spreadsheet to get a more accurate idea of what Options 1 and 2 will look like.