To answer your questions
My first question is: With those facts would it be worth it since I am not driving the system hard? I've heard that having additional amplification helps bring out more detail but is it significant? On the rare occasions when I am home alone I do love to push it though.
Yes, it is worth it. You will definitely get more detail out of your system and now your receiver is only being asked to drive your rears and do surround sound processing.
Question 2: Is the emo in a standby mode until it receives a signal through the speaker inputs from the receiver? Sort of like how my subwoofer is in standby until it gets a signal?
No, the Emotiva is on, unless you install a 12v trigger to it and your receiver. If you do this, then it will turn on, when the receiver powers on, so in essence, it would be in standby mode, but only with the 12v trigger attached.
Question 3:What is the difference between the balanced and unbalanced inputs?
Balanced connections require a round type plug that your receiver or pre/pro probably doesn't have. Unless you have a lot of interference in your room, you likely don't need this type of connection. The most common connections are stardard RCA interconnects, which are the same as the old L/R analog stereo connections we used to use before Digital Coax and Optical cables came into being. You can purchase really good interconnects from Blue Jean Cables. They make an LC-1 cable that I use and they work great.
I just recently purchased an XPA-2 and it is really nice. Great build quality and it sounds fantastic. I am using my receiver to power my Center Channel, which I am considering getting rid of anyway, since my Mains are imaging so well now and my rear speakers.
Bottom line, from what I've read, go with the Emotiva. You have a 30 day trial on it anyway and for the money, they build a very solid and great sounding Amp...