property rental and photography are not related so they are separate businesses and each would require a QBO subscription. The property business would benefit from the plus subscription since it has location and class reporting tags (same as class in QBDT)
two businesses also mean two schedule C's with your tax return
personal finance is never included in a business accounting file, you must keep them separate which at the minimum means separate checking and CC accounts. You can dedicate a personal CC to the business, it does not have to be a business CC specifically, but no personal transactions should be done using that business card
You ask for economical, QBO is 4-5 times the cost of desktop, with less functionality. There are hosting programs that will host mac QB, even that would be cheaper if you actually really need 24/7 anywhere access to the accounting.
this a non partisan comparison of QBO vs QB desktop is about windows desktop, you should know when something is mentioned in desktop and is in Mac,
http://onsale-apparel.com/Rustler/qbo-or-qbdt
(cost comparisons are at the end of the article)