Hi PP, you seem to have done your homework!! You have it all planned out and patience to boot. I like the v-drip idea and it sounds as if you have plenty of room in that closet.
Whats the NPK on your nutes? I used Vitalink Bloom with some Bio Bizz bud stimulant - very mild really with whats out there but it really made a difference when i started using it.
One single 400W for 12 plants is ambitious, it'll be fine for your veg but you may need 2 or 3 for flowering that many plants. Cover your closet walls in Mylar reflective sheeting.
Filter is good, I aint got one and im getting a bit smelly depending which way the wind blows, lol. Squirrel cage is good too.
I used soil as my medium, never used clay but i've read very good comments. If nothing else you can use them again
No, it sounds as if you have most things worked out. Enjoy your vacation and ill be looking out for your journal
All the best
