[LisaS]

2 - as might any trainee - not just obese clients
3 - or get a tape that is longer - they are available.
4 - as might any new trainee
5 - any trainee might have medical conditions - surely you screen all clients for diabetes, heart trouble, COPD, arthritis or any other actual medical condition. Also - any race person can get ancanthosis nigricans.
6 - why? what's the safety issue that high rep circuits circumvents
7 - fairly useless advice (find out the number) unless you include advice on what you would do differently if it was higher

I'd say look for medical conditions you should be aware of in all of your new clients, not just the morbidly obese and be prepared to accomodate any exercise scheme as as result. So, you might want to read up on any changes that you would make for the common conditions that any of your new trainees might come in with.

Now, larger clients might have issues due to their size outside of any disease state. For example, her center of gravity might make some standard movements more difficult or his size could make some movements quite uncomfortable - chafing and bouncing issues come to mind. Not to be crude, but ATG BW squats are an issue when your thighs hit your calves after a very small range of motion. Pushups or even planks can be an issue if there is too much of a belly to really clear the floor - so you might need to do slanted pushups and planks to get the effects you want. That sort of thing.
But you'd tailor any program to your clients individual movement issues and weaknesses, right?