Gaining an Order Affiliation and summoning

I just want to see if I understand orders correctly:

My sorceress starts with a 0D Journeyman affiliation with the Order of the Restless Dead.

If I want to summon an Imp from Hell, I would need to get a 0D Journeyman affiliation with lesser corporal spirits.
Once this affiliation is acquired I can attempt to summon all sorts of lesser corporal spirits, not exclusively creatures from Hell. I could summon a little angelic thing from Heaven if that is what I wanted, so long as it is a lesser corporal spirit. Yes?

Now the price to join this order of creature is based on the least of their prices of service. So if I wanted to get a Journeyman affiliation with the sanctified dead, the price would be some form of tribute.

But if I wanted to summon aforementioned Imp, then in order to get the journeyman affiliation with lesser corporal spirits, I would need to allow myself to be possessed by a spirit, as payment for the affiliation, yes?

I realize that I could also undertake a geas, but I’m just wanting to make sure I understand the price option, right.

You don’t ever form an affiliation with either heaven or hell or the planes of the faewylde or w/e, it’s just an order with a certain category of spirit, after which you can summon that order of spirit from anywhere in your game’s mythology, yes?

Is this correct?