I'm very curious on how plugins failed to compile. The only reason may be that the plugin have #include <dhudessage> which is built in AMXX 1.9 and you simply need to remove that line in order to compile. I'm 99% sure that everything else is just warnings that a new and better function exists, and this does not prevent plugin compilation.
Yes, 1.8.2 is stable. But also yes, 1.9 is better and has many new features ans bug-fixes. I've using 1.10 for years in many servers and haven't experienced any issues whatsoever.
If you're actually experiencing issues, you should report them ASAP and they usually get fixed quickly.