My sister got me a pretty cool mug(R2D2 mug, had to tell!) and I absolutely love it, I read at the bottom of it that it can't be put in the microwave nor the dishwasher, not sure why but something tells me it has to do with the "paint-job" I have it a work and heating water in one mug only to pour it in my mug seems tedious. Is there anything I can do to maybe make the structure/paint of the mug more durable, or an easier workaround for using a mug that cant be heated in the microwave (the washing part doesn't really bother me, I don't mind washing it manually)
Something about the mug interacts with the microwaves; almost certainly because it's conductive, so that it heats up in ways you wouldn't want it to. This means that you can't change the mug's non-microwave-friendliness without substantially changing the mug. For instance, if it's the coating/glaze/paint, then you'd have to remove it in order to make it non-conductive. If it's the mug material itself then you'd have to remove the mug itself to make it non-conductive (you'd have The Emperor's New Mug).
One test I've seen is to fill the possibly non-microwaveable container with water and then microwave it for twenty seconds at a time, seeing whether the water or the container heats up faster. If the container doesn't heat up you're fine. If it does, then you're stuck.
A mug like the one you received cannot be used in the microwave, and cannot be converted into one that can.
I have several mugs that fall into the same category.
My recommendation: Turn them into flower pots.
Unique drinking mugs make great flower pots, and you get to see them every day.
They even work great as "starter pots". You can put a few seeds in them, or even a small potato or garlic clove, and with a little soil and water, you'll have a beautiful plant in no time!