Hi Laura - welcome to tPP! Wow - I do like the LV Neverfull
If I had the funds, I'd probably go with the biggest size and use it for toting anything since I'm a sahm of two little ones! It would also make a wonderful commuting tote for those who work in offices. Those straps can withstand a LOT of weight according to the LV site! As for the thin-ness of the straps - pro would be that they would stay on the shoulder nicely but con would be that they might indeed hurt if you wore a heavily packed bag without a coat or jacket as a buffer. I happen to have a Fendi Zucchino tote with thin straps that do stay put on my shoulders. I think I have a pic in my thread under "Display your collection." Which reminds me that I need to update that collection to include my Chloe collection!