My beautiful 1993 plus 12 string came in the mail a few days ago. Now I have a dilemma as far is tuning is concerned.

I initially tuned it to D standard to put a little less tension on the neck. I know it's not necessary to do this after a lot of reading on the forums, but my band plays in D. After an hour or so, I decided I wanted to hear what it would sound like at concert pitch E standard, so I went ahead and did that. I noticed the neck bowing a little more (of course it would) and I quickly went back down to D, as I was not mentally prepared to touch the truss rods of my new baby.

After some thought I've decided I want to tune it back to standard because that's what everyone including Mr Hall recommends. My fear is that I will be destabilizing the neck by switching back and forth so many times. Are my fears justified? Or have I succombed to the new guitar paranoia?

Not justified at all. Get yourself a trussrod wrench and tune it however you like. It's a Rickenbacker!

If you're downtuning, I would suggest going up a string gauge.

No worries- your RIC has two, yes, two truss rods and has been built as strong as a tank. You will not warp or twist or loosen the neck; not even if you try; the guitar is well made.

RIC instruments are designed with the dual truss rod to handle a 12-string set in 10-gauge at standard pitch. Tune at will.

Think about it: the first three RIC 12-strings with the old-style truss rods are still going strong after over 56 years.