I have installed OSX in Parallels (10.8.5)... and Final Cut Pro (10.0.9). FCPX throws an alert stating that it will not run because the "graphics configuration" is not supported (referring to hardware acceleration). I doubt you will have much better success installing FCPX with Yosemite in Parellels. From the Parallels user forum:
“There's no hardware acceleration for OS X guests. Apple doesn't open their API so Parallels can't write the drivers.”
You can use Disk Utility to create a partition and install Yosemite creating essentially a dual-boot setup. You'll have to ask for more advice about 1) installing Yosemite into the partition (and not over your current OS) and 2) running apps from the other partition while in Yosemite. It's been too long a time for me to remember the details.
As for the Adobe software... I refuse to buy into the rent for life (subscription) paradigm. I used to use Photoshop on a daily basis. Now, I can do over 90% of what I want to do with Motion (all the video oriented graphics, to be sure.) As for replacements, the Affinity products (Design, Photo) have been receiving excellent reviews (Photo is still in beta, I believe.) [http://petapixel.com/2015/02/09/affinity-photo-new-pro-photoshop-alternative-mac -users-get-free/] Anyway, I've had it with Adobe.