In response to your question as to putting your mind at ease.
There is no set time span as to when training must be completed. We are very fortunate that we have in-house company trainers/evaluators/mentors. Our training program can last from a minimum of one (1) week up to three (3) weeks. We will never let a trainee go on their own until they have gone through formal (classroom) training by a certified trainer, then gone through hands-on training that is conducted by an evaluator and then gets placed on a crew and assigned to a mentor. Once an evaluator has signed off on his hands-on training he is allowed to drive independently but he is NOT placed on crew without being assigned to a crew mentor that is there for support and becoming familiar with the crew requirements.
There is no way we can justify saying a person should be totally trained and certified in a three day or week time span, it depends on the trainee and the trainers.
So back to your original question as to putting your mind at ease...well that is something that you have to be able to do and I think you can accomplish that by making sure that you do not just "certify" someone using a time span criteria and that you turly use a profiency span time line. As Dan stated in one of his responses, it is your signature stating that the lift truck operator is certified and ready to go, so please if you have any doubts, don't sign them off.