Here are the Specs on the KEF T101 -
Frequency response is 80Hz - 30kHz.
Impedance is a nominal 8 ohms.
Bass drivers are 115mm or 4.5".
1.) Will putting another pair of the little KEFs in front help at all?
What do you mean when you say "another pair"
? Do you mean the KIipsch and the Kef, or do you mean TWO Kef?
The key to making FOUR Front speakers work together is for them to be as close together as is physically possible. That is, assuming both pair are at the front of the room.
From my understanding, with TWO pair of front speakers, because of the distance between the speakers, there is the potential for comb filtering and lobing. However, I have FOUR Front speakers. But the gain I get in output and impact more than offsets what I lose in the combination. That's the nature of audio, a series of trade offs, and making sure what you gain in one area is more than what you lose in another area.
2.) Musicality and Imaging?
In my case, I have two pretty large Front speakers in a Stereo system. For music, I only use one pair. Though on rare occasion I use both. For movies, I absolutely use both speakers, the impact for movies is huge. Also the second set have a bit more midrange presence, which is good for movie dialog.
Now, I didn't set this system up intentionally. From buying new equipment, I have old speakers and amps laying around that were worth more to keep than they were to sell. So, I decided if I have them and they work well, I might as well use them.
But again, you will gain in some areas buy using two pair, but you will lose in other areas. The key is being able to place the speaker, actually the speaker drivers, as close together as is possible.
Whether you will get the same benefit that I do, or whether you will find the trade-offs acceptable, I can't say.
Lastly, it will depend on your amp, and how well it will tolerated the additional load. Though with an AV Receiver, you many have spare, as yet, unused amps available. But how they are connected to the amp and the general capacity of the amp will matter.