I would take a more cautious attitude than @Mogget. Anyone who is experienced and skilled is probably justified in feeling that he can try just about anything. But let me repeat here Debian guidelines to sysadm:
Do not install packages from random mixture of suites. It probably
breaks the package consistency which requires deep system management
knowledge, such as compiler ABI, library version, interpreter
The newbie Debian system administrator should stay with the stable
release of Debian while applying only security updates. I mean that
some of the following valid actions are better avoided, as a
precaution, until you understand the Debian system very well. Here are
Do not include testing or unstable in "/etc/apt/sources.list".
Do not mix standard Debian with other non-Debian archives such as
Ubuntu in "/etc/apt/sources.list".
Do not create "/etc/apt/preferences".
Do not change default behavior of package management tools through
configuration files without knowing their full impacts.
Do not install random packages by "dpkg -i ".
Do not ever install random packages by "dpkg --force-all -i
Do not erase or alter files in "/var/lib/dpkg/".
Do not overwrite system files by installing software programs directly
compiled from source.
Install them into "/usr/local" or "/opt", if needed.
The non-compatible effects caused by above actions to the Debian
package management system may leave your system unusable.
The serious Debian system administrator who runs mission critical
servers, should use extra precautions.
Do not install any packages including security updates from Debian
without thoroughly testing them with your particular configuration
under safe conditions.
You as the system administrator are responsible for your system in the
The long stability history of the Debian system is no guarantee by
Apologies for being pedantic.