Are Flying Blue Platinums always allowed in the SV First Class lounge, which I assume is the Alfursan International Lounge ?
yes
Do the lounge agents need to see the FB membership card with the boarding card?
yes, you'll be directed to J if you don't proactively flash your status
How cold is the lounge as I really don't like being cold if I'm just sat for hours?
A jumper is enough, you won't go hypothermic. Think of full blown aircon, American or Asian style, designed for businessmen in suits.
As mentioned by
Maz1982 . The added hassle is flying to and from TUN (I'm doing that from London). Tunisair must use a random number generator to build their timetable for the times and if using LHR or LGW
. BJ is an option but not the cheapest. There's no direct flight with BA or EZ, so AF via CDG seems the only realistic option due to the frequency (plus the FB Platinum benefits). Both before and after the SV TUN-JED-BKK flights an overnight in TUN will be required and some here have said to take a few days to explore the city, but it I do not have the time for that.
AF is more than decent for options. Managed to snag a positioning flight for £168, that's not the 2AM one
That 2AM looks as possibly a great option for you as you don't want to spend an extra night in TUN. (Just when I was about to think to myself nobody in the world would ever choose to board an A320 for a 3 hour flight between 2AM-5AM)
I'd still recommend the night in TUN on outbound for peace of mind.