Glaring omissions:
filter - plaits is a voice module - and has a built in filter - as part of the built in low pass gate - I wouldn't worry too much about this for now - if you're going to get a plaits though hurry up - last batch may already be out there - and if you're getting plaits I'd go for veils over the intellijel quad - it's a little smaller and has more features... but again - good luck in getting one...
a mixer would be a very good addition... vcas are extremely useful for both audio and modulation... both of the moons have them built in so don't 'need' to go through another vca... I'd add an inexpensive mixer - get one that's dc-coupled and when you come to upgrade your end of chain mixer, it it can be used for other things...
why are effects modules expensive? they're not necessarily - you're obviously looking at expensive ones... but a lot of the 'expensive' ones take a long time to develop, not just in terms of hardware, but also software - if you want cheap effects then you could also look at guitar pedals and pedal interfaces (AISynthesizers makes a DIY one that's pretty inexpensive)
I agree with Lugia about a bigger case - mantis is imo, one of the best starter cases there is especially because of the combination of decent power/manufacturer reputation/hp/cost
take a look at my signature - it's a simple guide to getting the most versatility out of your modular for the least cash - and scales well from the smallest to the biggest systems...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities