They are in outliner areas and seem to be growing rapidly because of their price points and lower taxes

From a Broker Level, you would need to evaluate what you are going to need as whether it will handle those needs.

Purchased first property through conventional financing on May 1st, 2018.. had around 30k saved and was able to get a lower down payment since i'm living in one side (all you guys know this process i'm sure) 10k in savings now.

I have a lot of confidence of on-going short-term rent appreciation (next 5 years) but less confidence of significant on-going property appreciation (I expect a leveling off but am not real confident of any prediction).High end homes (bigger and more expensive) have worse cash flow than middle class or working class homes.Note a small multiplex or your 16+ unit will experience similar rent and property appreciation to your SFR and have better initial cash flow (it will be poor initial cash for San Diego but increase with the rent appreciation).To summarize, SFR are not the best buy n hold investment option in San Diego. 

Lots of things can go wrong, and your lower income won’t give you much wiggle room.You can wait til you have 50k, but I think 30-35k is more manageable.

I really like the south ATL market but you need to know the market on a more granular level as some places haven't seen the same growth.

This book goes into detail about how different levels of income earners actually use their money and how each of them are taxed.

Could anybody please tell me if there are any other good options for foreigners to get lower downpayment and longer period?

If anything  it could pay your car note (if have one) each month (which lowers your monthly expenses).

Most of the homes in the MI/OP group are in very tough neighborhoods and much of the 46218 zip code are lower income/higher crime areas.