Not sure I am titled this clearly. The issue is this: If I am workjng in track view on a song that is say 80 measures long, when I switch to PRV my data is scrunched into the left side of the screen. Not a huge deal to zoom in to work on it but seems like the PRV should default to the length of the song. Maybe this is related the mysterious 'end of song' behavior where Sonar thinks songs are way longer than they are. Not sure. This happens to me on every project whether there is automation or not. 

You should only have to do that once, after which the PRV should default to whatever settings you last used.
 

If you mean for that project, yes it does. But every project starts that way. Not a big deal just seems odd that the programs assumes the project is sooo looong. Is there anyway to tell Sonar up front that a project will not exceed "x" bars??

What version of Sonar are you using (I sometimes get this when I open a very old Sonar project), and what do you use for a new project startup, a preset template ?
I'm just wondering if you're "Normal" start up template could be adjusted to get rid of the extra bars, then you wouldn't have it in any newer projects.
 
Also, have you checked the Event View to see if there is some stray data on a track, (maybe even a hidden track) in your project, for example at bar 300 ?

When I see this behavior, it is often because I have automation lanes extending far beyond the end of the track. I place an automation node at the END location, scroll to the right and delete any remaining automation nodes. As long as the automation lanes are "dashed" after the end, the problem generally does not occur.
 

I sometimes open PRV and find it fully zoomed out vertically, but never horizontally.
 

As B-flip said, I set this once and PRZ zoom settings are set that way for every project now.
I use templates 90% of the time but even when I don't,, this is the set default for every project (the one I selected on previous project).

I usually just start w blank template. Maybe that is the issue. I will make a few project templates and see if this is solved.