There are a few reasons the MC didn't do those things. First he wanted to live a lazy life without doing much work. So, bringing in things which would revolutionize the world wouldn't allow him to relax easily. Also, he only brought the instruction on how to create stuffs like homemade Soap and Shampoo, along with new type of recipes of food and alcohol, mainly because he wanted them (MC being a hygiene freak, made him focus more on Soap and Shampoo, since his supply that he brought was limited). Next he had only limited knowledge on stuff, and only showed interested on things he wanted. As for other stuff, he only showed interest in order to help the Queen, a.k.a, his wife (like with the Glass manufacturing method, or modifying some existing methods). Lastly, he didn't plan to be dependent on the Earth Technology for too long, since he knew that they had a limited life-span and he couldn't get them again easily. That's why he only brought stuff which helped him get past the initial adjustment years more easily. It was just recently that MC learned of the concept of rewinding the time on items, and understood that there won't be any life-span issue with his stuff (the Queen wants to mainly use that magic on his Laptop though, to help with Tax calculation for now). By the way, he didn't bring a PC, he brought one Laptop and one phone (not sure if it was smartphone or not).