Running the numbers through the bow speed calculator which I've found to be very accurate (http://backcountrybowhunting.com/articles/toolsOLD.php) and estimating your arrow weight to be 420 gr. (9.8 gpi x 29" plus insert and nock) I come up with a speed of 293 fps.
I don't think your 350s are too stiff. I had the same problem with my PSE DNA with almost the exact same set up as you 28.5" @ 63#. Shooting my 400s through the chrony I was getting 307 fps and it shot field tips very well. But I could not get my broadheads to match the field tip POI. I switched to 340s and all was well. A plus to using the 350s is they are slightly heavier giving you more KE.
As for sighting in - I'd sight my top pin for 20 yards. Then shoot at 30 and see where you hit. If the difference is minimal you can reset you pin for 30 and hold a bit low at 20. Now this is only if you have a multiple pin sight and plan on shooting at extreme distances as it should give you more spacing between you pins.
Good luck and enjoy.