Question re connection in BKK
 

I am flying BKK-HKG-YVR on CX. BKK-HKG flight leaves at 11:30.

I am flying from USM (Koh Samui) to BKK that morning on PG (Bangkok Airways). My understanding is that PG will allow me to check-in my bags all the way through to YVR: see http://www.bangkokair.com/informatio...ECK_IN&lang=en

If I arrive in BKK at 08:50, does this leave me ample time (2h40m) to catch my connecting CX flight to HKG? Will I need to check-in with CX in BKK or can PG issue me all of my boarding passes in USM?

Lots of time. BKK does not have the most efficient layout (it is actually one of the worst new airports in asia in respect of walking distances).
When arriving just look for signs for the transfer counters - there are two areas, so check on which side of the airport the CX counter is. It will take you between 5 and 15 min to get there.
After getting your CX BP go upstairs to the gate. This should take you also not more than 10 min or so.