Airliner and Biz Jet Fragility?

[Halo]

In flying MS Flight Sim 2004 I'm surprised by how carefully I need to watch overspeed on airliners and business jets.  Are they really so fragile that they come apart if throttles are left at high settings during level flight?

How many g's are contemporary airliners and biz jets stressed to?  Are they overpowered, and if so, why, e.g.,  mostly for low altitude and acceleration safety with max loads?

[Wolfala]

Thats not the main concern - engines aren't meant to be operated at 100 % of N1 for long periods of time which is what many in FS operate at as well as AH. Fact of the matter is, you climb at a cruise climb power setting to keep engine temp and vibration in check, and set cruise power when level which is maybe 60 or 70 % of N1 depending on yr endurance requirements. This is more then you need to know, but thats how it is supposed to be done.