That's the reason most commercial deals have a 5-7 year horizon, because the IRR usually starts declining after about 5-7 years, so it's better to take the capital out and redeploy it elsewhere (here's a simple example).

If you have a longer time horizon, I think it will be fine, even a great idea to buy a duplex, and rent out the other side, and/or possibly even individual rooms.

I have a feeling the dollar value will drop dramatically, stock market same, and in general I just feel a financial crisis is on the horizon.

It won't change it drastically but it will lengthen the time horizon or lessen the dollars you can put into your hold portfoliowhen you pick up those first flips you will not be able to 1031 out of them into buy and holds. 

State it firmly, follow thru and do it, and inform the tenant that having done so, he/she is responsible for the service fees.You might suggest that if he/she is uncomfortable with the issue, you would help to find another apt and rescind the lease (just let'm go, nothing but headaches on the horizon).

I also do not have any other investment opportunities on my immediate horizon, and it's passive money... 

Also, Interest rates are still at historic lows and although these low rates are likely causing inflated pricing in hard assets, a long term horizon should shelter you from any corrections.Consider a 2 or 3 unit property for a higher cash on cash potential.

I'm looking to expand my horizon and learn as much as possible and hopefully become a full time investor. 

I am just trying to do something new and expand my horizons! 

You really need to decide what Cap Rate/IRR is acceptable to you over your investment horizon, and go from there.