Hello Aalto,
your configuration looks good to me. As far as I understand, you're running both osmo-bts-trx and osmo-trx on the same machine. As can be seen from your logs, TRXC commands from osmo-bts-trx are received by osmo-trx:
<0002> Transceiver.cpp:778 [tid=140554180474624][chan=0] command is 'POWEROFF'
however the response messages from osmo-trx do not reach osmo-bts-trx:
<0002> Transceiver.cpp:923 [tid=140554180474624][chan=0] response is 'RSP POWEROFF 0' <000b> trx_if.c:185 phy0.0: No satisfactory response from transceiver(CMD POWEROFF)
Maybe your firewall is blocking traffic (udp/5701 and udp/5801) somehow? Could you please send us a *.pcap capture ('lo' interface)?
With best regards, Vadim Yanitskiy.