As a dive professional yourself responsible for the group then isn't it also your responsibility to assure all are capable and not allow incompetent folks to participate? While they likely would not tip and you may be out of a "job" You have to admit that you know it falls on you, If you are always having to check others air then who knowledgable with the site is guiding the dive and finding the cool stuff for the competent folks?
I also noticed you decided not to mention the part about working legally
Honestly, No.
The reality is that people will arrive with the correct cert card and up-to-date logbooks. In that situation I can only use the evidence in front of me.
My first boss gave me the best advice ever when it comes to taking out a new group of divers ' treat everyone like a muppet, until they prove you otherwise'.
Recently I had a diver who after 5 dives with me (bringing her to a total of 40) could still not figure out that she had to release air from her jacket when ascending. Normally halfway through the dive she would be finning straight down and I would have to go and release the butt-dump for her. I counselled her on this both above and below the water (she was OW) and still she could not get it. Her husband tipped me quite a lot and bought dinner and beers for my efforts.
So yes, I check air. Initially I check every ten minutes and then I set the interval based on the amount of air consumed so we can see the dive site and point out things. I also brief that I need to be told at 1500 psi and 700, however I'm lucky if people pay enough attention to their gauge to do this.
Work permits? You are kidding, right? You'd be lucky to find more than 20% of foreign intructors with a work permit in
any part of the world, let alone Honduras. In fact if you asked all the Instructors in Roatan without permits to take the week off when you arrived, there would be no-one to take you diving! Please do not be so naive as to complain about work permits or taxes. We work incredibly hard for our small salaries and yet you will always find us at work with a smile on our face and a willingness to help. Go down the post office and see how many happy people you see there.
I do not work for tips. I had the luxury of getting them while in Honduras, however they are not customary when you do not have U.S customers. It is American custom to tip, so tip. You'd tip in Starbucks, why not for someone that can potentially save your life if in trouble?