Great vids Greg. 

Personally I think anything you learn should be played extremely slowly and in tune.

In Irish playing, which you are probably aware of, they say that there are 3 speeds, practice which is very slow, medium getting used to the tune, playing at home and the like, and 2 lumped together, session speed which can be very quick depending on the musicians lol and dance speed, 2 which is always the same, and can be heard and watched with,Irish dancers on you tube.

I have never played sessions on violin but have on banjo, and they can get very quick, especially when the drink flows and being in tune matters less and less. In England, in Liverpool, they can get raucous, In Ireland were I haven't played in session and never would, but have been at hundreds they can get mad, especially if played for Irish people by Irish Musicians, and not for tourists.

Lilting banshee, cooleys reel, swallowtail are a few, but, they may have changed now as its around 5 years since I last played in one,  and tunes tend to go out of fashion.

In Ireland people turn up to play who are just wandering through, but they are all generally fine musicians who know all the tunes and can drop in at breakneck speed, you also often get things like they will expect fiddle breaks and banjo breaks, so you have to be good, no doubt about it, which is why I would never attempt to drop in one in Ireland.

Mate of mine pat, used to play in Dublin a lot, but believe it or not its  mostly things like oasis they play there, and you can sing along to let it be at the end of the night (everyone likes the beatles) If you ever go to Dublin by the way watch out as the price of beer goes up at 11 at night, catches  lot of people out, quite funny.