But I've watched a lot of cases carefully & studied enough of the law now to know there are ways to fight it in court.

Study the market.

My suggestion is to study first the numbers / cities / markets and once you know your zones / cities of interest, look for people who can help you locally.

I haven’t seen any longer term studies done, only promotional info when the RE market was generally rising.  

However, the problem is that I currently live in Northern Ireland and will go to university either at the University of Edinburg, in Scotland the London School of Economics to study economics and politics.

Note it often is not a result of significant NOI change (excluding some markets where a lot of new units have been added). 3 recent studies show it is cheaper to rent than own in virtually all of the largest US markets.  

Once you do get buy something, be sure to look at a cost segregation study for the property.  

Here's an article with additional FAQs on cost segregation studies that you may find helpful and should answer some of your questions above. 

I really can say that everything needs to be perfectly handled without any room for error.However, you do not need to go and study all aspects of Dodd/Frank, Safe Act, Senate Bill 43, the Property Code, the Finance Code, insurance law and all case law regarding wraps. 

A cost segregation study will help maximize these properties depreciation expenses in the early years.