In some cases it's useful to create a custom property and have the alert go to that. It makes updating recipients of alerts much quicker. If you don't have many alerts, this may not be useful to you, but in a large environment with hundreds of alert definitions, it sure helps. Create a new custom property named something like 'Email_recipient' or whatever you want.
That property can then be referenced in the To/ Cc/ Bcc fields.
You can just type in email addresses alert by alert, but if you need to scale, custom properties will probably save you time. From what you describe, you might benefit from copying existing alerts and making the new copies go to the different address.
That what I do too. Using advanced alerts I create an alert for each with custom properties as the catch for the alert
my custom properties that I use mostly are.
Here is one of my alerts that excludes switches and routers and sends an alert to everyone except my network team.
I also use some custom properties for remote locations management teams as well.
This one sends an alert to a specific management team about disk free space being low.
I don't think so. I pretty much use these fields for every system managed so there will be some sort of text there.