well - i tried a couple of setups yesterday. first i tried an ORTF pair of schoeps out in the room, plus a single DPA 4061 on the flute and a single 4061 on the piano. then i tried the two 4061s as a spaced pair out in the room, plus a single cmc64 on flute and a spaced pair of akg c480s on the piano.
out of all those potential mixing combinations, so far the best overall sound comes from the pair of spaced DPA 4061s out in the room. it almost works all by itself. i will spend the rest of today fooling around with more possibilities, such as mixing the ORTF pair with the spaced pair, or slightly supporting the DPA pair with a bit of the stereo piano and the close flute mic, putting reverb on just the room pair and none on the close mics (and vice versa), fooling with the phase on the close piano mics, using the close setup of the 4061s supported by a bit of the ORTF pair, etc, etc.
all in all, the room didnt suck as much as i expected, it certainly is not a good space for this type of recording, but it could have been much worse. thanks for your help.