[timoK]

I like the river c/r for the reasons rzk mentioned.
nitty mcnitterson might even fold a pocket pair due to the action (c/r is only bad if Lossy McSuckish has a pretty high WTS or low fold to raise on the river)

with these people in CO and BU raising A4 is not "that" bad.

however betting the flop into 4 players is borderline imo. you wont make all 4 fold on this board (+ you might have only 3 outs) but if Nitty or Loosy iso-raise you you might be in pretty deep [censored].

my play is:
raise preflop. c/c flop, c/f turn (and if the river is 3-handed I like the original fancy play)