Hello!
The sweet thing about Golgari is how flexible it is, and how many different directions it can go. What I like about your list is the emphasis on spells that are both green and black.
If budget isn't a concern, then
Grim Flayer and Mealstrom Pulse are incredible. Flayer lets you smooth out your draws for the next few turns, and feeds it's own Delirium. Pulse is incredible against tokens and any pesky permanent you can think of.
Some other great options that aren't quite so expensive are
Pharika, God of Affliction and Putrify (over
Go for the Throat). Pharika is pretty amazing here as your devotion will be so high so often it will basically always be an indestructible 5/5 for 3. It also lets you eat
dead creatures to make more guys (3/3 snakes with a Liege in play). Finally, Putrify is just powerful removal that is unconditional removal at instant speed. I could see keeping
Go for the Throat for speed, but that's what
Abrupt Decay is for. Plus, Putrify triggers Mimic
Hope this gives you some ideas. good luck!