Is bi amping worth it ?

@hardhattg 

I'm glad you got to hear AR9's way back when. I also heard Klipschorns many years ago and they did sound very good. It is a different kind of quality. I just read about and heard a discussion about their origin and Mr Klipsch. They began shortly after WWII and his story is quite entertaining. He even had something to say about early AR's, citing bullshit which became a bit of his mantra. He was quite a character. 

Anyway, 2 ohm would make me nervous but there are many here far more qualified than myself to answer that. There are builders and designers here. I am just an avid listener, who is still not deaf after nearly 73 years of listening to rather loud music...........within reason. 

@ghdprentice may be onto something. I know diddly about streaming and I don't know your primary source. I don't stream and I possibly never will. It is as important to me as having an HT system..........not at all. I'm just an old stereo geek. Check his sytem/systems out. He knows a thing or two as do a great number of the experts here. They have likely seen and heard it all.

Call me crazy but I consider my REL Stentor III to be my bi-amping solution. I use the Voxativ AC-1.6 full range drivers in a baffle, and I run a second line from my amp's speaker taps to the REL powered sub. I also used the REL when I was driving Wilson Sophia and Daedalus Ulysses V2. Why? They didn't need to bass support, but the sound was more open and transparent, which I attributed to using a separate amplifier for the lowest frequencies. 

Yes.

Not worth it. 
 

get a Schiit Loki Max for tone control to adjust the bass punch higher by a smidge. Then get a subwoofer or 2. 

It depends on what your goals are but generally yes, bi-amping will improve your sound.

In your case the Khorns were designed with bi-amping in mind, so you technically do not need an external crossover, but to realize the benefits of bi-amping you will need a way to adjust the gains of the amp(s) reproducing the mids and highs so if you do not have an amp that has adjustable gains, you probably will need an  active external crossover. The frequency dividing function of the external crossover will be of little benefit for you since you will still  be using the passive crossover in the Khorn.

One of the advantages of using an external active crossover is that you have the ability to set the crossover point for what works best for your room as opposed the predetermined crossover point that is hardwired at the factory.

One advantage of bi-amping a floor standing speaker is that you do not have to worry about any phase/timing issues.

Also keep in mind that you will be adding at least 4 more interconnect cables, and if you are running single ended, each of those new interconnects has the ability to pick up unwanted noise, not to mention that any noise picked up by the interconnects before the crossover will be amplified by the crossover gain stages, so if you have the ability to run balanced, you may want to consider doing that.