No, your LEGS are too weak! BWAHAAAHAAAHAA!

Seriously, tho, springs don't get weaker unless they're stressed past the yield point of the material from which they're made. No well-engineered derailleur has that problem. More likely they will snap.

The vibration may be partly from cross-chaining- Have you checked your chainline? The distance from the center of the seat tube to midway between the chainrings should be the same as the distance from the center of the dropouts (assuming the frame is aligned) to the middle cog.