What room is this in...are you expecting a lot of water on the floor so you have to worry about mold
? My brother installs professionally and I've never seen him seal the perimeter with caulk--or caulk the trim unless it's the 1950's plastic cove look! I've installed plenty myself but I'm in MN and the rules/recommendations might be different
. When glued properly, your floor shouldn't need edge caulk since your trim should hold down the edges.
I don't favor composit trim, but have worked with it. It does split so you will want to drill (but you have to patch which might be why they recommend glue). There should be no need to glue unless they tell you it tends to warp
, under which case you should look at different product
! Have fun!