I think you could veg for a couple weeks, but up to you really. LST helps when using lights that don't have good penetration like CFL's, so you may want to look into it. Could probably start in a couple days. Just don't train too much at once... little bit every few days.
As for the nutrients, I'd really go look up the instructions for everything before using them wrong. PK is meant for the middle stages of flowering, CannaBoost is only an additive, not a nutrient
CANNABOOST and should be used throughout flowering. Here's the Canna feeding schedule
CANNA TERRA FEEDING SCHEDULE
The Big Bud
(feeding schedule here) is for weeks 2-4 of flowering. I don't know much about Advanced Nutrients except that they are expensive.
If I were you I'd get the Canna Terra Flores, the Canna PK 13/14 (if you don't have it already) and stick to the schedule above.