I was assuming here that OP didn't have another source of 5V. I told them to use the breadboard supply because it's more replaceable than the Arduino in the case something goes wrong. I'm not suggesting that they should continue to use them for servos.
Also I have a very short little anecdote to share about hot regulators. When I was prototyping my combat robot, I decided it would be a good idea to charge LiPos off of my breadboard power supply. I connected the power supply to a cheap 1S LiPo charger board and then connected the charger board to the LiPos. The LiPos began charging, and they finished charging without a problem, but the breadboard power supply was hot almost to the point where I couldn't touch it. It still works though.
Considering that my breadboard power supply (200mA) could handle a task normally undertaken by a USB cable (2A), I think OP will be fine with a small servo for a quick proof-of-concept, especially if they are working with the same kit as I am (which they likely are).