[OciXCrom]

I'd say 1.9 is much more stable than 1.8.2 at the moment, especially having in fact all the bugfixes from previous versions and new additions. There's no reason to be afraid of upgrading to 1.9. Even there is a minor issue with it, it is highly unlikely to cause major issues in your server. If such an issue exists, you can easily report it and it will be fixed ASAP.

AMXX is backwards compatible. This means there aren't and won't be any breaking changes in newer AMXX versions. Compatibility with old plugins must be preserved. Upgrading won't break anything.

Not really sure how AMXX is related to custom maps, nonetheless crashing them.