When you say fun, fun with an eye to win, or just fun?
Either way, Typhus is bags of fun...until you get him into close combat with a dreadnought who hits you with a strength 10 power fist which causes instantdeath if you fail you 5++ ( I learnt this tonight...sigh.)...Other than that weakness, he is a close combat machine with some fun nurgle powers. I am in love with the finecast model too. Typhus oozes character. But perhaps the funnest thing about him is his ability to take Plague Zombies as troop choices! Once you pay the initial 50pts for 10, they are 4pts a model and you can create cheap hordes of zombies. What is more fun than that!?
Mantic Games do really cool boxes of zombies for fairly cheap (15£ for 35 I think) and ooze character and braaaaains....They play pretty well too, with FNP they make great meatshields and objective holders to work alongside your plague marines.
Daemon Prince: Nurgle marked, with wings and black mace is how I am going to run mine (when I get round to it), and I believe it's one of the more competitive builds. You can also have fun kitbashing a model as they don't do a winged plague daemon prince last time I checked...So that is fun from a modelling perspective.
Your Terminator squads are fine as deep striking anti-armour units. I run them like this too and they are quite effective, will regularly pop land raiders unless you are unlucky with deep striking...You can also take a lone Obliterator as an alternative if you want to save points, but obviously you have less melta shots (though they have twin-linked meltaguns), so it's completely optional and situation: Just another option to think about.
Plague Marines in their sacred number of 7. I like it. Fluffy build. Also I like the plasma. Melta is the other go-to choice but I always run plasma. Why not have 2 in each squad?
Raptors: Have only tried them recently, and that was with my khorne marked loadout with flamers in a big squad. I have no clue how nurgle marked Raptors would fair. I guess the +1T will help with small arms fire...I want to say khorne and slaanesh is the way forward with Raptors, but you are running a mono-god Nurgle list so I am not going to recommend this to you
Give them a go and see how they perform. Chances are with melta loadout as you have Nurgle is probably a good choice as you are not going to be in close combat...You are tank hunting. So +1 T probably makes sense.
Predator: I only ever use the anti-infantry version autocannon and HB sponsons and that is when I am playing Dark Angels...Honestly I have no clue about the lascannon variant, but for a similar price I would personally go for Havocs everytime as they seem more durable in cover and more flexible with missile launchers. But that is just me.
Definitely a nice core to build on you have though, for sure. No "bad units".
