Vinny, yes you should speak out. However the young chap advocated telling the PF what to do to correct the situation.
I have no problem with being told I am too high on the glide or I am turning on to the wrong taxi way, that is what I expect of a competent PM. If I miss something tell me, I wont be angry. However if you then tell.me.to put power on, lower the nose or even try to take over, you will a best get a bit of a telling off and at worse a visit to the chief pilot.
That is what I meant.
Once you are in a jet on the line,with a regular captain,you will realise he or she is very aware of what is going on, it is prudent to use good judgement. You will learn a lot on the line, not all of it good, but if you really want to upset a Captain, try telling them to add more power, which is what the young man was suggesting.
Sadly he has taken his write up of the Ryanair Selection day down, it was very informative for others.