Today, a support system for our main database application has crashed
without being able to update some rows. So it has locked those rows
and some users couldn't be able to enter data for those rows
getting "Deadlock" errors. So I killed all firebird processes
(firebird CS), and everthing was fine again.

There's a setting as DeadlockTimeout in the firebird.conf file. Is it
in use by default after installing firebird?
Can I use it? For ex, if an application has crashed, locking some
rows, it will be nice if the locks are gone after a minute.
Is this the feature I need?

Regards