Hi Ly,
1. Why not? Sure you can
2. Vcntl input resistance of AFE5808 is 200kOhm. Connecting 32 devices in parallel gives you 6250 Ohm.
Max TGC voltage is 1.5V, therefore you require 240uA. Max output current of OPA1632 is 150mA. Then answer is again: sure you can. However, while using such a number of devices, you should pay your attention on a very careful PCB layout. The TGC control signal must be noise free and its distribution should be relatively short to the target devices. For this reason it could be a good idea to use more then one OPA1632. It all depends on your PCB layout.
Best Regards,
Mariusz