Rice – Should parboiled rice be washed/rinsed before cooking

I did this in my restaurant for years, it really does work great. Make your rice in a huge batch, cook it as if you're planning to eat it then, but then let it cool until handlable. Once it is cool enough, bag it in individual servings and freeze it. Refrigerating cooked rice quickly ruins it, freezing it, however, works great. If your servings are fairly small, snack sized ziplocks work great for this, otherwise use sandwich sized. Make sure you press the air of the bags, I take all of the small bags and seal them together in gallon sized ziplocks to give them one more layer of protection in the freezer. Either with the rice solidly frozen, or at lunchtime (defrosted, cool rice), throw the baggie in the microwave. You don't even have to open the baggie, when it pops open that's a sign to check it. It may need a bit of a mix and a few more seconds in the microwave, or it may be done, it just needs to be heated through. The hot rice will be almost indistinguishable from freshly cooked. If you don't have a microwave, you can drop the sealed baggie into simmering water, or take the frozen or cool rice out of the bag and steam it to heat.

Once you get the hang of it, rice is as easy as pasta. One thing you say in the question that may be central to the difficulty you are having is that your lid is "half-closed". For the majority of rice cooking methods, not only should you keep the lid tightly closed, but you shouldn't even open it to check the rice until it has cooked close to long enough that it might be done. Look at the accepted answer here: Rice gets burnt and watery. That answer explains it more thoroughly.