Hi Mae, I am glad you are using the resources available to you. I jumped to completely the wrong conclusion and feared you were learning to play just by session practice which would be possible, but inefficient – Sorry. I agree you want a folk player! The most comprehensive way to get your questions answered would probably involve hopping on the train. London is close by and perfectly doable for lessons as I did it for a couple of years and Leeds usually only one change. Train and tube travel with a Pilgrim is easy enough, your new friend may be less convenient. Ailie Robertson is based in London at present, and I am sure there are other great Irish players there too.
My rare attempts at Irish music are rather lacking in the right feel, and for that matter effort or practice on my part, but have done the odd workshop (one was even called folk for classical players – very kindly we were given written music;-) ) and been an audience member quite a lot. My impression is that ornaments are mostly fingered the same as they would be if the same notes occurred in classical music. So for instance very often an upper grace note will be played with the thumb, but sometimes a 2 or 3 if they are nearer. The problem is getting the right relative weights of the notes which seems to be down to practice, control and hence technique. The main difference I have noticed is that the Irish ornaments tend to be fingered using the option which minimises the repeated use of one finger. So a trill dede which is a nice example even if you don’t want to play it can be fingered 2121 or 4321 with the 2 placing over the 3 (or 4231) and a turn edcd could be fingered 1231 or 2341 (or 1232). The second of these options seems to be the one more often chosen by Irish players, and is very often the one I would prefer for lighter ornaments in classical music. However, an alternative is that some players look to the wire string harp and use the thumb much less – see Bunting Vol 3 from p 24 http://imslp.org/wiki/The_Ancient_Music_of_Ireland_%28Bunting,_Edward%29 and http://andrewlawrenceking.com/category/early-harps/irish-harp-ornaments/
The one ornament I know which is used Irishly but I can’t remember every coming across classically (it doesn’t work so well on high tension) is a repeated note played by striking the same string with 4 3 2, feeling to me a bit like playing an arpeggiated chord that I haven’t placed in advance. You can see this in the second video above including at 25-30 seconds.
Andee, I rely on you contradict me on the ornament front, especially if I have the wrong end of something that isn’t even a stick! Apologies for my earlier outburst, I over react to feeling misinterpreted.