I am not very familiar with the Christian Indentity movement, so would not be a good source. My understanding has been that their belief system leads them to be more of a White Separatists group and that they view caucasian blood lines as directly descendant from Adam and the "chosen" people of God.
But, that is only an impression and should not be taken to the bank.
I believe anyone can accept Jesus Christ as their Savior and thus be acceptable to Him. I have many black, brown, yellow and every variety of pigmentation friend whom I would trust my life, and the life of my family to. Whom I would be proud to have in a fox hole with me fighting tyranny. The principles of liberty and of fundamental morality are far more important to me than one's skin color. It is upon those principles that I base my judgements.
The Christian Identity people, if they are separatists, have every right to be so and to believe that as long as they do not infringe on others. If they want to "live apart" in covenant communities ... more power to them ... just don't try and force others to do so.
If they believe in Christ's teachings and follow them ... and if they do not try and coerse or force others and are willing to accept similarly moral people of other races and creeds as brother and sister Americans (meaning people who are committed to American liberty and the Constitution) ... then they can be allies ... just like any other belief system. ... but as you see, a lot of this is based on "if's" that I am not sure of with resect to that particular belief system.
Regards.
I can't say I know much at all about Christian Identity, but if it's just living apart like you say, that seems a lot like the Amish and Mennonites are doing and that doesn't bother anyone.