If ur looking into flatland tricks, I would think the idea (counter-intuitive as it sounds) is not to try to detune your edges to the point of patheticness. Whilst this may be desirable for jibs, such ground tricks actually require very good (and precsie) edge control for the very reason that alot of them are not done on a flat base (unlike jibs) but instead require some kind of edge setting to create a platform to spin from. Catching an edge doing ground tricks of this nature will have very little to do with how rounded ur edges are and more to do with board control/timing/sense of what is your "uphill edge" whilst spinning around etc.
Beveled edges do help - tho they need not necessarily be bronze. And to refine what I just mentioned, you should de-tune ur board, but only at the wide hooky points. Not all the way thru.
Most noodles boards would do fine. Generally look for a board construction that is tortionally soft. Longtitude wise, it depends. A more snappy board is harder to press, but gets more pop when ur heaving off a nose/tail press into a 360 etc. So this is a matter of preference generally.