Questions on Khoros events for application subscription and bulk api

Hello,

I have a few questions for how events could be extracted from Khoros.

App subscriptions 
Bulk Api 

As far as I can tell application level subscriptions are few and don't have "id" parity with what exists in the bulk api, is there a way to tell if an event coming from the subscriptions is the same in the bulk api so we can deduplicate?

Are subscription webhooks guaranteed to deliver in case of target url downtime?

There doesn't seem to be a message.move event in bulk as opposed to subscriptions.
How could we tell if message X is relocated in another group for instance? or will it trigger a message update?

If a message got moved what happens to it's replies do they have a separate move event triggered or are we supposed to keep a hierarchy for the messages ourselves to redo the tree?

There seems to be no subscription event for group visibility changes or actions, how could we tell if messages should be public in this case?

Do user deletion events trigger application subscription events for messages that got modified?

Since subscriptions don't have all the events for content that we would need for gdpr / visibility enforcement, how real time are entries stored in the bulk api? are they guaranteed to be in order (do some events get added later instead of their produced ts?) 

Can we filter by event type / action.key the result of a bulk api call? as to get faster responses - we do not require view metrics and the like.