You are correct. They never fixed issues #2, #3, and #6 (as stated under "Vendor response".) Any half decent resolver properly randomizes both ports and txid not using the predictable libc random(), but nginx developers have staunchly refused to do so...
Nope! Still using ngx_random to generate packet IDs:
http://hg.nginx.org/nginx/file/tip/src/core/ngx_resolver.c#l...
And ngx_random is still #defined to random:
http://hg.nginx.org/nginx/file/tip/src/core/ngx_config.h#l57