And i have no credit card debt.

I can buy a 2-4 unit with 20% down vs conventional can only buy a 2-4 INVESTMENT property with 25% down 4. there are options where DSCR loans dont repot to personal credit, helps in not having to show a bunch of paperwork or not one person in a partnership has to carry the debt5. way less paperwork to close on this loan type vs a conventional loan. we care about the income of the property you're buying and it's ability to service the debt of the property whether we use long term rents income, lease income, or air dna/bnb income.6. easily buy in partnerships, add people to your operating agreement, its as easy as that so bring partners into a deal. helps with scaling and raising capital or getting partners involved7. gift funds allowed to close on these as well, and like I said earlier, there's only a 10day seasoning period of funds with some lenders so that means you can literally have a private money lender deposit money into your account 11 days before closing, and you can use those funds to close!

I'm an beside ER nurse netting over $160k/year raising a family of 4.

Purchase price: $520,000 Raised 100% of the funds to buy this property.

You've raised some excellent questions.

you can always call or email the tenant in regards to this matter. i personally smoke as well and just would want my tenants happy and not feeling accused as its a big problem with a lot of tenant v landlord situations around the country. you can always say you got a report of the odor of weed and was just verifying the smell with both tenants on the property. you can restate your conditions with smoking. you can always ask if they are legally able to do so as well (meaning medical card). depending on how you want to handle it, if you want to make it a legal warning to the tenant as well, you should write a written letter sent by mail stating you got a report of weed and this is a written warning in case this a problem down the road, you have evidence to show the court if it gets to that matter that this is not your first occurrence. best of luck!

I owned for 37 years, raised the rent many times, and later sold for 6X what I paid. 

While the economics are not as favorable for you, raising $300-$400k to buy something like a 1.2mm property will be far easier than trying to raise $10mm to buy a 100 unit.  

A couple quick points to some of the questions you raised.- Don't pay cash, leverage.

Or enter "for repairs" and take photographs of expensive new stuff for court...but they may be paying down credit cards.