All the big ticket items were just replaced in the past 5 years. 

Do they really pay enough interest to itemize?

I am asking experienced investors in terms of what I need to be careful about, basically what are some big items that I need to make sure of?

This can get you into trouble if you do not fully understand every detail of each income and expense item. 

Everything Greg said is definitely correct and probably highest priority diligence items, though I would move leases to the bottom of the list and rely on the Property's rent roll until you're further into the process.

It is very difficult to use just one item to make a determination. 

1.What are some of the recommended home inspection items - do you usually stick with the standard ones offered by the inspection companies or should we conduct radon/mold testing or anything else in addition?

Here are the main items that I see as of right now:- raise the roof/ ceilings- ??

You’ll have savings for your down payment, you can qualify for a better mortgage, and you can use some reserves, in case you need to replace a big ticket item sooner than expected. 

@Andrey Rudenko - I have itemized my costs by room where possible but the data is incomplete.