Robots would not naturally fit into the normal world of minecraft IMHO. The planet and the wildlife just doesnt support that idea. If he implemented travel to the moon via rockets or something like that he could easily implement them on the moon and make it an extremely hostile environment. You have to wear your quantum suit like a space suit because of the lack of a proper atmosphere. The robots would work perfectly for a situation like this. You can make it so that the robots drop some tech4 items(nanites?) and then you can add a few more mined items to the moon which would all be needed for tech4 items. If you didnt mine doing a little bit of restructuring you could make the t4 items things such as the teleporter and energy field generator. The matter generator would have to stay t3 as its needed for the quantum suit.
Also, is it at all possible to make it so that the netherworld would be positioned below the normal world so to speak? By that I mean you would have to place the portal at the lower levels of the map and it would spawn you in to the upper levels of the netherworld... That would give it a more natural transition since the lower levels of the netherworld are all full of lava.
These are all ideas to think on and implement with time as industrial craft grows. Yes I know i posted about more than robots =P
BTW you can EASILY! use a mod like this in your porfolio =P Its very complicated, well liked, and over time you have made it more sophisticated yet also more efficient. It reflects your knowledge of programming and your skill growth quite well IMHO. I know a guy that got a job as VP of a major corporation and his leading edge over the other people similar to him was that he stated that he owned and ran a corporation in EVE which had over 4000 active members and controlled a large portion of the industry in the game. Something like that teaches you management skills and jobs are recognizing game related accomplishments more and more lately.
Edit* Sorry just read in another thread that you dont want to add another dimension as its too much work. =( Although I still think this is a good area to stage an extremely hostile environment for people. You can even make lightning creepers naturally spawn there =P