www.walkera.com go there and look on the home page there's a link to a setup guide both for the tx&rx and measurements for all linkages just look for 4g3 setup guide mine does none of what your describing also if that don't help check to see if the feathering shaft is bent(the fastest way to tell is take one blade off use a #000 phillips screw driver turn the screw and see if the grips stay perfectly still as you spin the screw) if not replace it if that's not it try the main shaft next these parts are so small the slightest vibration or imperfection causes massive problems take your time and try that manual look over it all, cracked tail boom? blade tracking gear mesh on the tail motor? but my guess by your description is to much pitch and vibration if you hold it by the servo's and spool it up it and you feel any vibration at all it's not going to fly. also to tighten up the sloppy rotor head take out the feathering shaft and grind it down to 21/32th's of an inch it will fly much better!