There could be any number of reasons why this is happening. Could you post the fragment of the error log showing what happens when you manually try to start the bundle?

AFAIK AEM Forms is a standalone product that you can use in your own environment. The other marketing cloud products (such as Analytics, Target, etc.) are not needed for AEM Form. However, integration will other marketing cloud products will provide additional enhancement to AEM Form should you need...

Since you have removed all these config in the repository, I would suggest doing a search under the crux-quckstart folder in the file system for such configuration files and remove them.

The simplest solution that I can think of is to create a an empty page with the exact same name on the author instance. Then activate and deactivate the page.

Have you thought about using shared datastore between the primary and standby to reduce the overhead associated with migrating binary files?

If all the above-mentioned configurations do not address the issue, I would take a look at the template code to see how it is handling redirecting. You can modify the status in the code as needed.

Can you find within the thread dumps to see which thread is holding onto this lock "0x2a446ba5"? This would tell you which thread is blocking this thread in question.

If the issue is happening on every folder in DAM, I would suggest trying to recompile all the JSP pages [1]. If not, there might be an issue with the content within the folder. I would check the validity of each asset in the folder.[1] http://localhost:4502/system/console/slingjsp

If none of these possibilities could explain why you got the SNFE, I would recommend opening a ticket with the support team to assist further. If you have a reproducible scenario, it would be even better.

Can you verify your link checker transformer config to ensure that  link checking is turn on?