I switched a 4 string to BEAD and played it that way for over a year while waiting for my 5. (Even now that I have a 5, and I won't play the old 4 except in an emergency, I'll leave it set that way.)
To do it properly, you will need to adjust the slots in both the nut and the bridge saddles - and you probably can't go back
You could do the V thing on both, rather than the preferable U, and then just adjust heights. If you think this will just be temporary, then that would be wise. But if you find you like it, then go for the U, and deal with a new nut and saddles if you ever need to switch back.
Whether you have to mess with the truss rod and other stuff depends on the strings. It's possible you could end up with a BEAD set that has the same overall tension as your EADG, and the truss rod would be fine. But it's not that much of a mess, so I wouldn't let that put you off.
Pickups, well, that's a sound thing, and bigger strings are going to sound different, so maybe. But it will probably be an optimization, not a make-or-break kind of thing.
As someone mentioned in a recent thread on why more strings, I happen to prefer the sound of playing higher on a lower four, and doubt I would ever have an EADG setup again. But I have no idea what Stanley does, or why.
-Bob
