"Is there a 'non durable' longbow??"
Only one that I know of--the claim was made by the bowyer and a representative that the string (that came with the bow) caused the limb to twist. That was never resolved--a friend of mine lost about $1,000 on that deal...
Which brings me to my point. Stuff happens. Longbows are, in general, much less susceptable to things like limb twist, but any bowyer can make a mistake, get bad material, etc. Do your homework and make sure the bowyer stands behind his work. Don't take word of mouth as a guarantee (as my friend did), or even what's stated on a web site (that can be changed at any moment). Get it in writing. Better safe than sorry. I'd say this wouldn't happen with 99% of the bowyers around, but you still have to watch for that 1%.