Should there be a y-glide after the n in críochnóidh mé?

The speaker I'm listening to has it, but it seems out of place given the spelling.

with the 'ch' slender as well (i.e. as if it were "críchneoidh")? If so, probably dialect variation (though I couldn't tell you for sure which dialect); if not, probably a mistake.

Well, is your speaker a Gaeltacht speaker ? If so, it may be a dialectal variation I don't know. If he isn't, it's probably a mistake...
If the n is slender, probably the ch is slender too... as Aibí wrote : críchneoidh.

This is the problem, I don't know if he's a native speaker or not. His name is Réamonn Ó Cléirigh, an American from the northeast, based on his English. His Irish is plainly suberb, but whether he's bi-lingual from birth or just a gifted but non-native linguist -- I just don't know.

http://www.philo-celtic.com/PII/Progress.htm

Actually, Séamas Ó Neachtain would probably know! Séamas, if you're reading this, what say you?

The sound of these recordings is very bad, I wonder why. Anyway, what I hear on the recordings is not native Irish. The native sounds aren't there.

"whether he's bi-lingual from birth or just a gifted but non-native linguist -- I just don't know. "

He is obviously not native, and it sounds like there is two different speakers...maybe it took him so long, his Irish had time to change!

Which recording did your example come from?

I had to go back and look. Lesson 16.

The guy who reads most of the words just makes most of the pronunciation mistakes the average learner does. Irish is one of the few languages for which learning stuff is mostly recorded by non-native speakers who don't master the sounds - no wonder that most learners never manage to get rid of their English accent and sounds !
Mór an truaighe é.

But Lughaidh, for English speaking learners, broad and slender can't exist. Impossible, so there is no possibility that they could ever learn them

I'm curious where you hear him making mistakes regarding broad and slender?

I heard the slender n' where I would have expected a broad n, but other than that he pronounced words roughly as I would expect. Of course, I'm not exactly an authority, so I'm curious where else his pronunciation may be differing. Thanks.

quote:

I'm curious where you hear him making mistakes regarding broad and slender?

the r's, sometimes l's... I would find other examples if I listened again to it. And the sound is so bad, sometimes I even don't recognize the Irish word till the English translation is given...

quote:

But Lughaidh, for English speaking learners, broad and slender can't exist. Impossible, so there is no possibility that they could ever learn them

For French-speaking learners broad and slender can't exist either, but I've managed to pronounce them... :-)
With small efforts anybody can manage to pronounce them. But the problem is that many learners don't want to make efforts.