madMT

Hello all, I am having some problems with a somewhat twitchy Airtronics Rival sport AM radio system. The system is about four years old but really hasn't seen that much use. When the radio was new it worked very well, but now it has about half the range, and glitches quite a bit when the battery still has about half it's charge left.
I have a new Rs4 MT, the wires are all extremely short, the esc and servo connectors I have shortened to only necessary length, my motors have built-in capacitors, and I installed a brand new antenna on my Rx at the hobby shop. Other precautions include keeping the Rx 3in from the esc and about 5in from the motor, but it is right next to the servo and the battery. I have even tried using an Rx battery pack, but the improvements were only slight.
I have read up a little on the issue and am wondering if any of you have had experience with any of the following procedures, or if you have any of your own

-I guess you are supposed to keep esc, motor and Rx at least 4in apart (difficult in my MT)?
-I should mount the Rx and its crystal as high as possible (difficult, but doable I guess)?
-I should shield the receiver in Mylar or aluminum foil?

personal concerns:
-should the antenna not go near the esc or motor?
-should the wires to the esc and servo not touch carbon fiber, should they be factory length, ie not shortened?
-do my motors need maintenance?

Thank you all for your insight into this issue.