ramping the speed up and down in a controlled way and that implies some pretty accurate position feedback
Providing the acceleration and deceleration of the mass keeps the torque within the limits of the stepper motor the position will be known to the accuracy of the stepper motor. The system is open loop, feedback is not required. Problems should only arise if the motors limits are exceeded and it slips, proper use and design should eliminate this.
Is the turning 110kg weight because it will be someone holding a camera?
Because in that case you ought to motorize an office chair.
100kg because on the long term I plan on using the platform for 3D scanning of people. Long long term shot. Side project. Ignore this completely. Don't bother giving suggestions for this.
I live in an industrial city, oil and gas, so there might be every now and then an occasion to shoot an object VR of a heavy industrial piece of equipment.
Motorizing on office chair is not a bad idea at all.
I don't imagine I will be using the platform to spin objects right at the limit of it's capacity .. which will probably be determined by loading it with progressively higher loads till it fails. 99% of the time it will be under 10kg.
As soon as get the basics going, I plan on implementing some routine in program that will ramp up and down the movement between the required positions.
Speed ? Don't need it to go that fast. 10 degrees is probably the highest resolution / density that I am going to use. And if I can do a full object VR in under 5min that's good enough for me. That will be 300sec / 36 positions so about 8 sec / step. Plenty of time to move, stop, take picture.
Shooting while the object is turning is not something that I will do. Sync speed on the flash is probably fast enough 1/250sec and it could freeze movement but I still wont do it. That's how fast the shutter speed is while using a flash. The real issue is recycling time. The studio flashes or the camera mount flash need .5sec to reload and I think I am being generous. So, at 10degree resolution, you need something faster than that unless you want to go really slow. It is better to stop and go. Synchronizing duration of a revolution with camera triggering and flash reloading seems more difficult than doing it one step at a time.
I do need the table working at a 60-70 cm height from the ground. I can't get the studio lights lower than that. And I need to take care of my back 
Will keep posting here once I make some more progress. Waiting for new parts.
Thanks for all advice !