In the process group level availability monitoring you can change what needs to happen for a problem to be created. This is for individual process groups. This might help to make sure your monitoring is up if you set this on your key process groups.
To get alerts, an alerting profile is just the criteria that needs to be met for users and groups to actually see the problems that are relevant for them but does not by itself send alerts. You would need to add an email under the integration settings and fill in the recipients and assign it to the right alerting profile.
this is true for every process group type except for the Oneagent and Security Gateway ones (or probably for the type Dynatrace). You can't set anything for process group and even the edit button is missing. Same for logs - you can't view Dynatrace Oneagent / Security GW logs in Dynatrace, even if the functionality (viewing log files) is there and works for every other application.