If what you said about certain people being born with their subtle bodies misplaced, and that it will have an affect on the likeliness of their bodies being possessed during a projection is true, then wouldnt they be as good as screwed over by now :\ and every time they go to sleep...

If the astral is the dream world, then it's as dangerous as a dream and you're as likely to be possessed or not accessible when you get back as you are every night - aka not at all :\
You'd have to be incredibly weak minded to have your body stolen, although the fact that the etheric body would still reside within the physical during a projection of the astral double raises my doubts as to how possible it even is to become possessed.

On another note, AFAIK the astral resides in the 4th dimension, the mental plane in the 5th, so on and so forth, but don't quote me on that - its indirect knowledge.

@ the rhetorical question about your love: get them to project with you I've heard it can be downright incredible

meh.. ignore me, I'm a n00b