writing a grok pattern or any normalization with only a single message is nearly impossible. But I would do first a Key-Value extraction on the message or better, just use the CEF input - as this is a CEF message …
But not sure if all of your messages are CEF from that device.
For the second question: No You can only have one Input on the same Network and Port. Should you need different extractors or normalizations on messages coming in on the same input, I would advice to use the processing pipeline rules as they are more flexible on that.