Six month training then OK to go
Horse puckey on the 18 month training. Training does take awhile but normally six months seems to be average whether type rated or not. Those over 50 need a couple more simulator sessions but nothing arduous.
Jet Star likely having regulatory issues but this is only speculation. Japanese companies in my experience are good to work for. The only bug in the system is the JCAB licensing inquisitions. Some of the inspectors (not all) are miserable in the question periods. Examination through humiliations and intimidation.
Aircraft are well maintained. F/Os well trained though may be inexperienced and have difficulty hand flying the aircraft. They learn quickly, though.