If you are trying to search the content of the PDF I agree with @Madalyn_Destafney that this is not possible within Workfront

Yes you are correct, once the 100000 number sequence runs out it will be 200000 and on

I am 99% certain that the original person retains the same permissions - even if someone has been delegated ownership it should not mean that the original assignee has anything removed.  I would love to be proven wrong though!

I think you would want your proofing workflow to be configured so that each stage is active on proof creation - see screenshot

You are so correct! I am being asked to build a "single deliverable process" and "multiple-deliverable process" in tandem but what we are calling multi-deliverables is actually what Workfront defines as a campaign

We are struggling with many of the same issues - I definitely feel your pain. We had different requests being filtered through different queues but the recent directive has been to combine them all into one singular request form and oh my gosh is it confusing to manage on the back end in the form bu...

I can't wait to see some of my fellow Workfront people!

You can also create a template which assigns a specific person or role to any position of responsibility within the project.  Owner, Stakeholder, Resource Manager, you can assign specific tasks, etc.

Unfortunately, I do not think what you want to achieve is possible.  If it were me I would open a help desk ticket and ask a question to the proofing experts.  I don't think there's a way to combine anything in ProofHQ.