Exact same here – Had got used to it crashing every now and again before, but since latest update (and thus forced update to Yosemite, which I didn’t want to do purely because I’ve lost all trust in Apple’s stability with its updates anymore!) It can crash within minutes of reopening, then manage a few hours. Done everything bar a reinstall, but in middle of project now so will have to wait before I do that (for second time!). If I wasn’t so busy, I’d dump it altogether and learn Premiere or Resolve: so, so angry with how chronically the standards have dropped within Apple now. 15 years using various derivatives of Final Cut Pro, but I’m ready to jump ship now – just sick of it!
Oh, and I send report each and every time before anyone asks – though it’s been months now, and still no word on an update!
Sorry for rant, just so unbelievably frustrating when it impacts on my work so much!!! :/