Without parking, can if that line has visibility on other extensions can this be done? How? Can a park slot be established and the same park slot always be used for a specific line then if there is a call at that park slot blink the line button on the phone.... This is a pretty core use case to the small business....

You can do this will call pickup.  On the softkey, go to PickUp, then dial the ext that has the caller on hold.

Again, in a typical small business they won't have visibility to the extension #'s at all - they will have only used soft-keys in day-by-day operation.  We are about to deploy our demo system so we have less knowledge than many...Let me spell out a typical use case...

Tom is Sales Rep, Jane is Admin...

Jane answers phone, Tom is on the phone, Jane puts call on hold and goes over to Tom's desk to put a post-it note under Tom's nose.  Jane then goes off for a smoking break.  Call lost? Tom needs to know Park slot? 

Jane answers phone, Tom is on the phone.  Jane blind transfers call to Tom because he pissed her off this morning.  Tom sees caller ID it's a big customer.  He presses hold then answers ringing line.  Is 1st call disconnected?

What is the proper workflow and expectations for offices used to key systems?

-Aaron