Is ISIS executing a genocidal agenda with their destruction of cultural and religious sites?

That is a rather narrow definition of genocide.
The University of Hawaii offers the following definition from the International Criminal Court.
Genocide is foremost an international crime for which individuals, no matter how high in authority, may be indicted, tried, and punished by the International Criminal Court (ICC). According to Article 6 of the ICC Statute, This crime involves, "any of the following acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, as such:
(a) Killing members of the group;
(b) Causing serious bodily or mental harm to members of the group;
(c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part;
(d) Imposing measures intended to prevent births within the group;
(e) Forcibly transferring children of the group to another group."

I would offer that the intentional destruction of artifacts from a group which has been killed or exiled from a region is a sign and symptom of a genocidal agenda.

Interesting... I'd consider the killing or exile of a group as evidence of of a genocidal agenda.

They have been going after the Kurds and trying to wipe them out. I do know from other sources they are taking young female children as slaves. First they kill the men and take all the women and do what they are prone to doing under those circumstances.

Hell it seems to be the Current in Thing anyway. Look what the Israelis are doing to Palestinian Cultural Sites.

They already killed or chased Christians and certain ethnic groups out of the areas they control.