My Suggestion is to add 2 items.
The transmitter and the receiver.
To use it put the Transmitter on a MFE or MFSU and the receiver on a wall in you house.
Then link both with the FreqTrans.
Now the receiver display how many energy is in the MFE or MFSU.
You can also link more then one transmitter to one reciever.
Then they would display it like this 35688/120000 (with 2 transmitter/MFE).
You can also put a transmitter on a cable.
Then the Reciever would display how many eu go trough the cable (EU/s)
The transmitter should look like a little antenna and the reciever should lokk similar to a sign.
The crafting recipes shouldn´t be so expensive so that you can make enough for all your MFE.
By the way the idea of a limited range isn´t so bad
PS: Sorry for my English