Can you be listed on an organ registry of people who have similar diseases to you so you can get organs quicker?
Not really but..... The one exception i can think of is the case for kidney transplant in recipients that have hepatitis c. We don't give deceased donor kidneys from patients with exposure to hepatitis c to recipients that have never been exposed. The transmission rate approaches 100%. But for those recipients who have had hepatitis c, they can get a kidney quicker if they will agree to accept a hepatitis c organ.
No. Cadaver organs are allocated regionally by organ procurement organizations (opos). Each opo maintains a list for each organ in their region. Being on multiple lists in the same opo therefore confers no advantage. Being listed in multiple opos, may shorten waiting time.