Teacher/mentor is a question I've been asking since I got back too. I used to have mentors, as well as be a mentor and I'm not so sure they're necessary. Spiritual exploration is good when there is someone to guide you, but chances are they're on a new path as well, just slightly farther down the road.
As for ego? Well, if you find a good teacher it shouldn't be a problem. But, one of the interesting things that religions try to teach is that we are supposed to give ourselves over to someone so completely that we are no longer a single person. Rather, we achieve a state of ego loss where (though not in the sci-fi sense) we become a collective conscious. I think it's more like knowing that we are all the same. Doing something for someone else is the same as doing things for oneself.
It's kinda like Adam Smith's cooperation theories. Doing things to help others is to help ourselves in an indirect fashion (My knowledge of this really comes from "A Beautiful Mind", so I am incomplete). It's more like "Stranger in a Strange Land" where the main character keeps says "Thou Art God" as a worshipful phrase to all his friends. It's true, really, in both respects. If were are as God, then we are infinite as god and can be all the same being.
Shamanistic belief says that Tunkashila (God, closer translation is Great Spirit) is in everything and everyone. It is so hard to think then that we are all connected on a primeval level? If we can really attain perfect spirituality then we lose ourselves completely but retain the perfect parts of us. We are still ourselves but become a better US.
You should read Techno-shamans in Texas. They suggest that the new collective consciousness is the internet. It is just a gathering of all the information of this age into one easily accessed area. I don't think it will become so freakish uberdemon like in every anime ever produced (specifically Lain and Evangelion and .Hack) but there may be a day when we do lose our consciousness into the bit stream. Shouldn't God be in there too? I mean, electricity is a pure energy form. But it has the right touch of man. Pure Data and Pure Energy. hmm.
This is all in a perfect evolution of the world though.
Interesting (and lengthy) response to your entry, né?
Hmm.. I think I"m going to post this as a more coherent addendum to my recent posts.