Yes 4 chairs for the roof top pool if you don't count the cabanas which are not immediately besides the pool. Plenty of chairs in the main pool however and that's where the bulk people go (they stay in residences though).

Regarding rates, think again! If you saw 7k THB then it was most likely the residences, not the suites. So you would not have access to the roof top pool, no Club / happy hour either, and your breakfast won't be nearly as good as if you book the suites. The suites are far more expensive than 7k THB.

Suites used to be 16.5k THB on hyatt.com and recently the price has been trending up to 18k THB or so. As usual, it's cheaper on SLH.com, but in this particular case you can pay even less if you book straight with the hotel rather than SLH.com so cash prices on Hyatt.com have a double premium embedded; in most cases it will be best to book straight with the hotel unless you really need the Hyatt night credits. Or book with Hyatt points - 25k pts is not that bad and only marginally more than PH at 20k pts. I saw rates as low as 12k THB for the suites at 137P if you book by multiples of 3 nights and that price level is comparable to booking a suite outright at PH, except that you don't earn night credits or points, and in my situation I reach elite status at both Hyatt and SLH without needing more credits so I don't mind booking direct, and in high occupancy PH can be more expensive than this. As an extra perk if you book direct at 137P, check out time is guaranteed 24 hrs so check-in at 8pm and you will have check-out 8pm guaranteed. If you book with Hyatt or SLH then it's 2pm check-out.

It's in part due to this price level that almost everything was quiet and exclusive, it contributes to the roof top pool not being crowded, even with only 4 chairs. I was there in a period of high occupancy, went there on two different afternoons. One we were alone, the other there was only one other woman.