iMovie '09 migration to iMovie 10.x - need input

Ok, so after much delay, I have finally made a leap on my Mac Pro -- migrating from Snow Leopard to Yosemite. iPhoto to Photos migration of old Libraries appear to have been successful.

But with about Terabyte or so of raw DV footage (imported from Sony DV and Canon camcorders) in my iMovie Library I don't want go down the wrong path. Who has time for that right?!!

As the subject line references, all of this footage was imported with iMovie '09 (patched as long as they were offered). I never purchases iLife '11 because I couldn't put a large multi-year genealogy project at risk with downtime, etc., as I can only do this stuff on weekends. So, I have already purchased the current version of iMovie and its time to see what the iMovie '09 footage (all raw Events - no Projects) looks like in the current version of iMovie.

For starters, this thread has me concerned - iMovie 10 to 9 downgrade procedure

However, since I don't have any projects mid-stream perhaps the above thread shouldn't concern me. Nevertheless, if there are issue with aspect ratios not being respected as originally recorded/imported, I need some feedback.

I have cloned a different drive in my Mac Pro and want to have all home video on that drive. I thought I cold simply create a symbolic link in my user's home folder pointing the "Movies" folder over to the real thing that has "iMovie Events" and "iMovie Projects". However, it appears that iMovie doesn't follow the link as it opens - never prompts asking whether to migrate Events - and just shows an empty event list. Again, I really didn't have any projects mid-stream. So, its only the events (raw dv footage) that I care about.

Appreciate any advice you have on my situation with this migration and desire to use a separate drive for my video footage.

Thanks,

cougar90