For default_tz_uuid, please refer:

http://pubs.vmware.com/NSX-62/index.jsp?topic=%2Fcom.vmware.nsx.admin.doc%2FGUID-CFFD8F7C-7561-4FCE-8A4B-F483C44051F3.html&resultof=%22transport%22%20%22zone%22 (pubs.vmware.com_time_zone)

Following post is on adding gateway service, but might be helpful in terms of default_l3_gw_service_uuid

http://blog.scottlowe.org/2014/02/26/learning-nsx-part-9-adding-a-gateway-service/ (Adding GW)