I would say that yes, all of those things and possibly more are on topic.
The reason I think this is because when I first learned about Area51 and started using it, there was another proposal for mechanical engineering and I remember reading peoples comments about EE.SE and others that might overlap. The general consensus seemed to be that an SE site that is too specific/niche is not good at building the right sort of user-base to make it a good site (especially during the beta), and broader sites with a good tagging system are better. Some even commented that if Engineering.SE existed before, then there would be no need for EE.SE and this would be a better situation. I considered the various points made by people on both sides of this and came to the conclusion that my initial thoughts (that a larger number of smaller/specific sites was better) were wrong.
Here is an example of two related betas that failed:
And one in definition:
And a third site currently in beta that could possibly benefit from having all the people from all three of those above sites on-board (if they are considered on-topic):
So if the people in robotics consider those things on-topic and use appropriate tags for those subjects it might really help their beta to not fail.
The guys at SE obviously have a lot of experience with this kind of thing and know that a site needs a critical mass in order to be successful and attract the right kinds of users, questions, and answers. The rules for making a beta succeed come from this experience. So yes... all those things should be on-topic :)
See also the question Should my idea be part of an existing site, or its own site? in the Area51 FAQ.
Start looking at the tags to see what sort of sub-sites could be subsumed then go find them on Area51 and tell all those guys to come join this beta when it's public.