You won't find a long literature about this...but I believe, cadet or not, airbus or not that having your hand on TL when gear is up is good airmanship.
Below 5000' AGL, I don't see any reason why your hand should be on your arm rest...
About your fear that this might lead to a wrong/involuntary TL movement after an event...I'd like to say that this has more to do with proper training than just having your hand on the TL.
What do your SOP exactly say? Is there anything clear about it?
Out of curiosity: where is your right hand when you taxi?