1. i will configure around 15 different servers (autodiscovery, setting modification for Tomcat). I will give other users acess to Hyperic. I would like to save the configuration and in case if somebody will modify it, i want to be able to apply the saved configuration.
2. i think it is not possible, however i will ask. i have 5 servers with exactly the same application, server ports, everything is the same. is it possible to save configuration for the first one and apply it to the second. i know about i can use Edit Monitoring Defaults, but i would like to make template configuration for the entire server (several application).
In your first use case, it sounds as if what you are wanting is some sort of configuration versioning...or at the very least, some form of roll-back to a "last-known-good" state. HQ currently does not support that within the application. If what you are really asking here has more to do with backups, then you could accomplish this outside of the application by way of backing up the database HQ is using to store its data.
Your second use case sounds like something that Platform Cloning (http://support.hyperic.com/display/DOC/ui-Inventory.Platform.Clone) handles in HQ Enterprise.
It may also be possible to fashion a slightly less elegant solution to this problem using the "resource" command provided by the HQ API (http://support.hyperic.com/display/DOC/HQApi+resource+command).
I suggest viewing the documentation on database backup found here: http://support.hyperic.com/display/DOC/Database+Backup+and+Recovery. It is best to perform full backups of the entire database on regular intervals for disaster recovery purposes. "Disaster", in this case, can cover outright failure or destruction, or malicious or accidental configuraton changes. The latter seems to be the center of your concern.