I too can list disadvantages of any and every system mentioned.

i think you can run into alot of disadvantages to be honest. 

The disadvantage is that you have more people you have to serve and deal with.  

It can be a disadvantage in general to disclose you're an agent because any home that you inquire on MLS and the selling agent find out you're also an agent and investor they become more laxidasical and rely on you to find out more information than if you were asking questions for your buyer who is not as well educated in real estate.  

Steven Hamilton II - are there any good flow charts that show entity and clearly show different tax advantages/disadvantages?

Everyone has to do this, including hotels, so it's really not a disadvantage to anyone to have to charge this, although there are some that are "skirting" the tax law there (HI is starting to crack down on these "Illegal" vacation rentals).  

I'll preface this by saying that that flips are generally going to be considered inventory and therefore not subject to capital gains, short or long term, so if you flip a property and hold it greater than 12 months, it's still subject to your ordinary income rates and SE tax unless it's a one-off flip.An LLC offers no tax advantage or disadvantage .

When you're investing from afar, there's a high probability that you're at a disadvantage.

It is not that you can't do a IRA, but boy once you compare the two you will realize just how many disadvantages the IRA has (along with a SEP too); where-as the 401k does not.

As suggested, landlording in a true war zone is a full contact sport where you are at a huge disadvantage if you play by the rules, because the tennants typically do not.