An Lon Dubh wrote:
I hope that makes some kind of sense!
That makes perfect sense and I understand every word of what you're saying.

But I still wonder in which cases the object precedes the verbal noun (with 'a' as a connection) rather than follow it.
To use your example: In which grammatical context would you get a construction like
'....an bhróg sin a dhéanamh'?
My intuition says it's when a whole sentence is used as a complement of, say, an adjective:
'Bhí sé deacair an bhróg sin a dhéanamh.' Is that right?
Your tarrang-example is another construction that is troubling me.
If I understand you correctly, one should always imagine the English translation to be a noun. Hence the person the action is done to (grammatically the patient) has to be expressed with the use of the possessive pronoun.
Now, one of my examples is:
'Níl sé féaráilte mé a teaseáil mar seo.' (teaseáil being derived from the English tease)
Would you say that is ungrammatical in Irish? Would it have to be
'Níl sé féaráilte bheith ag/do/? mo teaseáil.'? Or is mé okay because there is no ag-construction?
BTW, I don't care much for the Caighdeán here, anything that people would say in any dialect is good for me.