My intepretation :

1. 3rd House Financing - 3rd Property Financing to be taken with any financiers.  Financiers can check the financing via CCRIS which will report under House Financing.  I believed it will be irrespective under Single or Joint.  So as long as 2, 90% and 3rd falls into 70%.

2. Borrower term is subjective, could be individual or company.  Best singled out both - 70% if 3rd property but Company, not sure if check Directors too. 

Should be clear in few days time, as usual govt loves to give out vague guidelines.