"that the bodhran plays TO THE MUSIC _ IT DOES NOT SET A SO-CALLED "RHYTHM" FOR IT."
Thank you for noticing that.
the bodrhan should dance,sing,follow and lead the same as any instrument played well in the context of a session.
If you get in a decent session with players who are accomplished enough to be unafraid of allowing that it sounds great and is great fun to play.
Of course some sessions are just a competition and the music comes a poor second to the ego's of all concerned.
Trouble is its more likely in the average session that all the instruments capable of playing the melody will all be doing just that, all at the same time, all the time.
Step back and let it flow?
Not very likely.