So, it should not void the warranty as long as it does not cause the problem. I will say that electrical are not something someone should alter with out some care. As for increasing brightness. I will say this, it is unpopular but the truth.
Most 3rd party lights are way brighter then stock, because they are way brighter then stock, they will blind oncoming traffic. Unless the bulb is a direct copy of the original, and designed for the projector, the bulb will create glare for oncoming traffic. Remember upgrading your lamp will need to upgrade your projector. Now most states it is illegal to have excessive glare on your car. Some states like California it is illegal to change your lights. It is a several hundred dollar ticket when you are pulled over.
I understand that you think your headlights are dangerous, but upgrading will not make it safer for you, you are now just blinding oncoming traffic.
So what can you do? There might be 3rd party kits for you. You need to have them professionally installed with a person that as a glare chart. They can upgrade and adjust your lights increase brightness and reduce the glare, but you will always be some glare. This will cost a couple of thousands of dollars. If you are really handy you can do it yourself, but you will need to replace both the lamp and projector.
What every one that tells you to upgrade your headlights will not tell you to have them tested by Department of transportation. In fact, they will be complete crickets on actually have them tested by the state.
Bottomline.
Your cars projector is built for the lamp. It is built for the lamp of that brightness, size, and set at the proper angle/distance. When you change the lamp size, shape, brightness, angle, or distance, you will create a problem. You will need to match the new projector with the new bulb, to make sure you are getting the right light output.