I believe they glue the parts together just to ensure that nothing starts unscrewing on you as you use it. (Threaded parts in general aren't known for staying together particularly well if they experience repeated impacts, as would be seen when dueling. Unless the parts are tightened with tools rather than by hand. But then you won't be able to take the threads apart by hand, or maybe at all. Plus the tools could damage the nice looking saber parts. But anyways....)
A blow dryer shouldn't hurt the electronics. The wires and sound board can withstand the heat put out by heat guns used for shrink wrap, and a blow dryer outside of the saber shouldn't add significantly more heat than that. If the saber hilt isn't starting to burn your hands, the parts inside are probably fine. (And you shouldn't get the hilt hot enough to burn you. If your saber gets that hot, put the dryer away and find cold water. You will not disassemble your saber today.) You only want to get the joint just hot enough to loosen the glue on the threads, so warm to the touch but probably not "hot".
Parts being "aligned" refers to how well they line up when put together. For example, making sure the switch looks like it's in the middle of the saber rather than off at a weird angle, with the switch section twisted wrong. In some sabers, the alignment makes a huge difference in appearance. In the Gladius, however, this shouldn't be a problem. (All parts of the Gladius, aside from the switch section, are axially symmetric and look the same no matter how much you turn them.)
If you do want to re-align saber parts, it is typically done with the use of "timing shims" (available on the website) and possibly sanding down the female-end threaded section of a part. These methods together help you twist your section to where you want it to be.