Stephan, here is the part that I think needs to be explored carefully:
First, Irenaeus is establishing the truthfulness/trustworthiness of Luke:
As Luke was present at all these occurrences, he carefully noted them down in writing,
Since we just got quotes from Irenaeus we see that he is talking about the activities in Acts -- ie the 'we' passages in which Luke was present...
Next, Irenaeus shows the strong link to Paul:
so that he cannot be convicted of falsehood or boastfulness, because all these [particulars] proved both that he was senior to all those who now teach otherwise, and that he was not ignorant of the truth. That he was not merely a follower, but also a fellow-labourer of the apostles, but especially of Paul, Paul has himself declared also in the Epistles, saying: "Demas hath forsaken me, ... and is departed unto Thessalonica; Crescens to Galatia, Titus to Dalmatia. Only Luke is with me."(1) From this he shows that he was always attached to and inseparable from him. And again he says, in the Epistle to the Colossians: "Luke, the beloved physician, greets you."(2)
NOW to his point against the heretics:
But surely if Luke, who always preached in company with Paul, and is called by him "the beloved," and with him performed the work of an evangelist, and was entrusted to hand down to us a Gospel, learned nothing different from him (Paul), as has been pointed out from his words, how can these men, who were never attached to Paul, boast that they have learned hidden and unspeakable mysteries?
Clearly to me Irenaeus is saying that there are men/heretics falsely claiming they have gotten mysteries from Paul. He says it is false because he basically says their claims are not found in Luke-Acts, and if ANYONE had gotten those great mysteries from Paul it would have Luke. What he doesn't say is that that GLuke was written during Paul's lifetime--rather the 'we' passages in Acts were. It appears Irenaeus thought GLuke to not be in contradiction to anything Paul preached, but that's a long ways from saying that Paul's 'gospel' was GLuke or that there was some original GLuke that was different than the one we have now!
I do not see that 2 Timothy 4 helps anything other than to bolster the idea that Luke was close to Paul, and Paul had some writings, but again there is no reason to conclude that Paul's writings were his 'gospel', or that Luke wrote them, or that Luke's GLuke was Paul's 'gospel' from anything presented so far on this thread.
Indeed the section actually begins with a discussion of what we see concluded here - i.e. that Paul speaks of 'hidden and unspeakable mysteries' so this is a closed 'unit' as it were from Irenaeus.
From what I see Irenaeus was denying the 'hidden mysteries' claimed by heretics to have come from Paul on the grounds that they are not found in GLuke or Acts. Is this, for you, a case of one who protests too much? You have called Irenaeus a liar many times, yet seem to want to find the 'truth' by scrutinizing his words in order to find out if they betray certain truths. That seems a worthy goal, but I'm not seeing what you're seeing in this particular thread.
So again Paul was alive when Luke wrote his gospel is clearly implied. Not from 2 Timothy 4 alone (but Trobisch makes that argument) but from Irenaeus's use of this text after an explicitly chronological account of Paul's (alleged) ministry. In other words, the point at which Acts ends (= the two year stay in Rome) is the date of the composition of Luke which precedes it.
I see no reason to conclude any of that. Acts, yes (or so Irenaeus thought). GLuke? No, nor that Irenaeus was claiming it was Pauls' gospel'. In any case, why would that matter? Irenaeus could have been wrong if he thought that. What he clearly IS saying is that whatever the heretics were claiming as hidden knowledge wasn't in GLuke. So, how does one dispute that? I don't think it is by looking for clues that GLuke was Paul's gospel. Even if Paul were here and said "Luke wrote down my gospel' how would that change anything at all? Would that overturn the orthodox position on anything? NO. It seems to me that only an analysis of what supposedly was in the 'original' Gluke vs what is there now is going to be helpful -- not an analysis about what Irenaeus has to say about which gospel came first and if it was Lukes -- unless I'm missing some nuances there.
And if (as I would allege) the end of Acts and all this nonsense in the Pastorals is a colossal fabrication written by Irenaeus to use against the heretics rather than being texts 'discovered' by Irenaeus, Irenaeus's application of the material is the correct one (as he is the original author).
you lost me on that one..