Hhm, that's quite the list! Meaning you probably will want to be prepared for everything ;-)
As for syncing things up the pro way, look at the ACME4 ( http://www.schneidersladen.de/en/snd-acme4.html ).
You will want a MIDI interface in your modular, probably going both ways. If you plan on sending CV from the computer to the modular you will need a special interface like the ES-1 (http://www.expert-sleepers.co.uk/es1.html) .Question 3. Are you looking into processing outboard audio inside the modular? That would need interfaces for each chan to bring the outside line level up to modular voltage and another interface module for bringing it back down for the mixer.
Start by looking at the interfaces of your most important boxes and get modules to connect them to your modular. To have all the connecting options you will face about a complete row of interfacing. See http://www.expert-sleepers.co.uk/hardware.html for inspiration.
At a minimum, you need a module that accepts and syncs to audible clicks/triggers and outputs a trigger or gate to sync your modules. Stick your drum machine's rim shot in it and your modules will follow the drum tempo. Probably both Maths and Disting can do that, read the manuals.
PS: Only saw your updated rack after posting.
Do you already have the Make Noise CV bus module?
AFAIK it is sold as part of their shared system only.