perhaps a silly question Flowering time

You can maintains your plants in veg for as long as you like. But when you turn them into flowering, that's when the timer start. But keep in minds it's just a general indication: you plant gonna need about this time, but one plant may need more time, when another one from the same strain may gonna be faster. You still need to watch your plants all along.

Typically I refer to the total time as cycle time. Flowering in this case would most likely mean that the stage of flowering is 8 weeks, so veg is not included in that cycle time. Is this an autoflower or photoperiod? If it's an autoflower, it's possible cycle time could be 8 weeks, but if it's the latter I would assume they are referencing 8 weeks of flowering time as just that stage.

Generally yes, but of course all girls are different and your main signal that she's ready is your trichromes. Once they are milky white she's ready, but you can let her go even longer to get the more sedative effects by letting some trichromes turn golden amber color but be mindful that this color indicates your past max THC potency. Hope this helps and good luck👍🏻