Hello...
 
Is there any difference between inserting a compressor plug in into the FX bin versus putting it in the pro channel? 

No.

Here is a good read from SOS Magazine about the Pro Channel and it's Fx being using within Pro Channel and within the FX Bin.
 
SOS Magazine Pro Channel

I have question about that. What is the Priority of pro channel vs bin vs region effect ARA? Thanks

NONE.

Pro channel can be set before or after normal fx bin. So priority no issue.

Region fx are processed at clip level when you create and then process the clip.

Of the Region fx plugins, only Melodyne can be used as a normal VST 2 or VST3 plugin but then you lose the ARA benefits

Unless I'm mistaken, you can only use compressors that are ProChannel compatible on the ProChannel.
 
As far as priority, this is from the docs...
 
To route ProChannel pre-FX Rack or post-FX Rack
By default, the ProChannel signal is routed prior to the channel’s FX Rack (pre). To route ProChannel after the FX Rack (post), right-click any empty space in ProChannel and select Post-FX Rack on the pop-up menu.
 
https://www.cakewalk.com/Documentation?product=SONAR&language=3&help=ProChannel.10.html

You can create an fx chain with anything you like in it and insert that into ProChannel.

mudgel
You can create an fx chain with anything you like in it and insert that into ProChannel.

Yes, just like the link I posted explains.