Dear Tom
Unfortunately, in relation to the Timothy Donoghue men listed in Griffith's, there are limited avenues in relation to finding out more about them, due to the vacuum in records. That is why the system of linking researchers and people in individual parishes is so important. While we don't have anyone working as a liaison in in Blarney, I will attempt to find a volunteer who can help you further.
The earlier source, the Tithe Applotment Books date between 1823 and 1837 while the next, later source is the 1901 Census.
http://titheapplotmentbooks.nationalarchives.ie/search/tab/home.jsp
The Cancelled Books are very useful but as you can see from the link you posted, the LDS microfilm version are in black and white. The Books themselves need to be seen in their original colour as the 'cancelled' aspect of the Books appears in different colours as tenure passes from one to the other. As this is the case, if you wanted to progress this side of your research, you could contact one of the genealogical companies who could send someone to the Valuation for you. It is time consuming work but very worthwhile.
In relation to Whitechurch, it is a Cavil Parish where the corresponding Roman Catholic Parish is Blarney/Garrycoyle, so yes, you are correct.
Hope you had a nice weekend
Regards
Clare Doyle
Genealogy Support