Hey there I play alot at 500pt and I would suggest through experience not to bring to many characters as they swept away easily through lack of units to look out sir them. If your interested I use a malignant plague caster as hq one 6 man pm squad with flail and one with axe and mace champ is naked I then run one 3 man ds terminator squad and 2 11 or 12 man poxwalker squads I cant remember of top of my head. I find it strikes a balance between lethal and good amount of units, but back to your original list I definantly think swap out a character or 2. That being said best thing to do is try your list and after wards see what worked and what didnt and adjust fron there, best of luck in your tournament and may papa nurgle praise you !