The advices given previously are pretty good.
One thing I do when a hotel has no locker or feels unsafe. Just give your valuables in a very regular (if not cheap) bag to the receptionist. And take a picture with him, cheeeeeese. If anything happens to it, you at least know who took it from you. Don’t put cash in that bag.
Regarding safes/rooms being broken into, like everywhere in the world, staff has a copy of all doors and locks. Bring your own lock with you if you use a safe from a hotel.
Another thing: uglify your gear. Make it look older, broken, low quality. Some people put tape around their cameras to do that, you can add any other sticky material. For your computer, you can first put a plastic shell to it and then put loads of ugly tape and stickers to it, the day you are back in a safe place you can simply remove the shell and it’ll look as new.
Finally, get a decent travel belongings insurance. In some regions of the world it’s considered exceptional to be able to travel for several months without getting robbed (yes I look at you Latin America!). Make sure you back up your work to the cloud as often as possible and keep good track of your computer setup (it can take days to setup a computer from scratch, nevermind if you don’t know exactly what it was). I’m no expert at this field, but there might be some service providing the option to take full images of your computer every now and then, so if it’s stolen you can at least have a look at that image and possibly restore it to a new computer.