does the LV brass hardware... rot eventually?? or stay the same?

I think it takes years of daily use to chip. Tarnishing comes quicker, but can be cleaned off with a brass cleaner like Brasso. Don't let that prevent you from getting any LV bags, though!!!
 
I think it also depends on the 'type' of brass LV uses. I find the more expensive bags have shinier, heavier, and much more stronger brass than say those from the mono, damier and mini lin lines.