Operator "AND" "OR" in the flow

You can do that by using choices in the flow steps.

Use Add Choice in a Flow Step - Marketo Docs - Product Docs

You'll only be able to evaluate one at a time---the first choice that matches will be the one that is applied, but if you use a combination of flow steps with choices in each, that should work

You could also do this by making use of the Request Campaign flow step.  Basically you wouldn't try to run any logic in your flow, you'd just push the lead to a different campaign through the Request Campaign flow step, and that new campaign's smart list would then qualify them for whatever logic you wanted.  If they qualified through the new smart campaign's smart list then they'd get pushed to the flow, where you could have the alert sent out, and if they don't qualify then nothing will happen.

The best part is, they'll still continue through the original flow as well, and by having a separate campaign setup to send the alerts you can call it from multiple places!

John