what "right" dots do you want Michael - the original pdf's that O'Carolan sent to the printers? As Undecided says, its the right dots if they remind you of the tune you want to remember. They aren't (and as said before CAN'T BE) be an accurate representation of a tune that continually varies from time to time and place to place, simply an approximation. But they are very probably an accurate representation of one particular "performance", or how one particular musician remembers the tune.
And yes of course the whole point of learning the tunes is to get out there and play with others (barring some perverse musical onanism).
re crap sessions, it takes time to sort the wheat from the chaff, the good session may be miles away or your mates don't like the pub....: and if you're a reasonable player isn't there some sort of moral obligation to support the inexperienced?