1. No, only 1 BTS can use one EDAP field, 3 TS in your case. You should define that EDAP in BTS manager and create EDAP on BSC (ZESE) and attach it to TRX. Read NED
2. Not really. That only means that subscribers going to use EGRPS from this BTS with EDAP will share those 3 TS. And the actual bitrate depends on quality, cell load, EDAP utilization…