Lookup field entering the wrong record

Hey there!
I just started using Zoho and am totally into it.

Anyhow, I have a list of prisoners seeking penpals. The idea is that I have this form Pen-Pal Pairs that so I can associate the "free world" pen-pal with the incarcerated pen-pal, who is already listed in our database (links at top of page): http://www.blackandpink.org/prison-penpals/

I tried it a few times, and I find that the lookup is choosing a similarly named prisoner (ie Michael Young, not Christopher Young) even when I carefully and specifically click the right person. Going in to edit the record, it won't change. I added a second lookup field in case the first one was bugged, but they both do it.

Ideally, I want a many-to-many relationship... "Free world" pen-pals can have many prisoner pen-pals and vice-versa. Do I need to enable a bi-directional relationship to do that? I had thought that the bi-directional relationship was only necessary if I was going to add "free world" pen-pals via the prisoner pen-pal application.

Also, I should note that I have the Prisoner Profiles form in a different application than the Pen-Pal Pairs form. I'm not sure that this is necessary / a good idea, but I didn't see advice on it and it seemed like a simple way to manage multiple forms and views.

In sum:
1)Thoughts on why it's putting the wrong record in?
2)Thoughts on many-to-many relationships in the simplest way possible for free-world pen-pals visiting the site?
3)Thoughts on if I should have all of the data within the same application (and if so, can I migrate the forms)?

THANKS!
~Reed