"Chaotic" would be a charitable way to describe it. Seriously allow yourself a good 3-4 hours from arrival at the airport to get to your gate.

From memory, these are the individual queues one must pass thru:

(1) Entry into the airport (check travel documents, x-ray luggage)
(2) Weigh luggage (note: this is done on a cira 1930's scale by three guys who take turns seeing how slowly they can do this process). This queue is also in close proximity to, and thus intermingled with the check-in queue. However, there is no marking/barrier/sign to indicate what line you should be in. I saw lots of people wait in the check-in line, only to be turned back to the baggage wiegh-in line.
(3) Check-in: They also weigh you bags electronically, again
(4) Check Travel documents, prior to entry into the next area to ...
(5) Pay 500 pesos for the privilege of flying out of MNL
(6) Immigration. This one takes the longest. Count on a good hour or more in an underairconditioned room crammed with a thousand or so edgy people. Agents seem to compete with each other for slowest processing time.

Now you can go to your lounge and relax for a few minutes. But don't assume you will just waltz to your gate ...

(7) Pre-security screening document check
(8) Security screening (luggage x-ray, pass thru metal detector). BTW, they seem to turn up the gain on the metal detector so that even the slightest amount of metal will set off alarms.
(9) Post security screening body search .... assume the position
(10) Pre-gate document check
(11) Hand luggage inspection: all carry-on luggage is inspected prior to entering the gate area
(12)Boarding


Some words of advice ... Allow yourself lots of time, figure out what line you need to be in before entering the queues, try not to get impatient (it won't help), manage to get a lounge invitation just to give yourself a break from all the lines, and bring a good book. And when you arrive in BKK, you will kiss the ground in thanks for being in such an efficient airport.

WRT the TG lounge, someone else may have an answer ....

have fun