What you are seeing is normal for your kit. The sediment, aka lees, is simply a collection of yeast cells, pectin, etc. There is no need to stir a kit, unless the instructions advise you to do so...and this kit will not have you stir the must like a non-kit wine. Your instructions, as you read in "2", will tell you to leave the thick sediment behind when you rack...so you want this to start clearing. And "3" tells you to eventually stir, which has to do with the formulation of the clearing process in a kit.
And to clarify:
-the primary is a fermenter, a bucket-carboy-bin-lug, etc., in which the initial ferment starts;
-a secondary usually means the contents of primary are transferred to a "secondary container" to allow initial ferment to complete, most commonly the secondary is a fresh carboy.
-to complicate matters there is 'secondary fermentation', meaning a second fermentation is induced, ie malolactic bacteria(MLB) are introduced, or sometimes it is spontaneous. Kits typically do not go thru secondary fermentation, though I've read of people adding MLB to kits.
--You will find the play on words related to secondary container vs secondary fermentation is quite common & most think it is due to wording in kit instructions. Even your WE kit has 1 Primary Fermentation, 2 Secondary Fermentation; this can quickly confuse new winemakers, especially when starting with kits.