To be or ot to be...Collared?!?!

I had thoughts running through my mind about vanilla versus D/s type relationships.  In the vanilla world, you have the union of marriage.  In D/s, M/s, and any other combination you can think of, you have marriage, but you also have the act of being collared.  Maybe I think about it wrong, but to me being collared is something similar to marriage in the D/s world.  It is a union of the two souls for the purposes of this lifestyle.

For now I just want to ask about being collared.  I realize my question, which is just out of curiosity, is a bit subjective.  I also realize that a lot of couples were already married when they began delving into the D/s world.  Much my questions for my readers are these:

1. How long should you see someone before considering collaring someone or being collared.?
2. How much experience should you have?
3. Do you think it is like marriage, and you just know when it's right?
4. Do you consider it similar to marriage for a vanilla couple?
5. Waht are your thoughts on collaring?

I'm just curious about the subject and want to know what my readers think about this, the act of it, the symbolism of it, etc...