Working in a hospital

While OHR shuts down within 5 seconds if it can't detect anything (eg. taking it off at night). However, the proximity of the pocket fabric means it is likely to stay on. But I don't believe this will drain any faster than wearing it on your wrist (about 7% per day).

It will detect steps in your pocket. Although perhaps not quite as accurately as dedicated waistband pedometer??

Sounds good enough for me, can i manuely turn on and off the OHR sensor ?

Scroll to HR Widget (Press UP/DOWN) > Menu (Hold UP) > Heart Rate Options (Press START) > Change Status to Off (Press START)

If your HR widget is next to the watchface, it's 4 button presses. Unfortunately, you can't do it in fewer.

It's best to manually turn off the OHR when not in use. Automatic turning off only works when the watch is stationary (as in taken off and placed on table). If the watch is in your pockets it will continue to try to find a pulse.

If you work in a hospital, I wouldn't worry about your daily steps, pretty sure you hit any health related target anyway. I average over 20k steps a day (usually hitting 10k by noon) simply because my job means being on my feet all the time, and leading a very active life in all other aspects as well adds to that. I think Activity Tracking is only useful for people who have a hard time hitting recommended targets for whatever reason, that's why at some point I stopped worrying about activity tracking and just use my 935 for actual workouts.

I thought that FR935 is normally used by people that do sport regularly and don't care about steps (and move alert), that are for triathletes (or any other runners) completely useless.

I have a 935, am not a triathlete and use both step count and move alert :-) I run and bike and have a power meter so that narrows which watches I can use. I have a sedentary job where I can sit for long periods so the move alert gets me up and out of my chair and walking so I don’t cease.

I think for many people, while they use the watch for it's fitness features, it's also their day-to-day watch, and do watch things like steps, use it for notifications, check the weather, etc.

There's going to be some features not everyone uses, but they are used. For me, an example is floors. I live in a one story house and in a very flat area, so I have to go out of my way to get a single "floor", while for others, they watch their floor count.