Depends
A lot depends on the files, like mentioned above. I have had to keep rendering with certain files but not on my miniDV videos from consumer cameras.
Yes it can be a pain depending on what your doing, though I prefer FCE and FCP even for simple editing over iMovie. So it's comes down to how much time you have, and if FCE is better for what your doing.
When I got stuck in FC I would go to my local bookstore and read a few pages on certain topics. Cheaper then buying another book, plus you may get your answer faster then online. Though I always checked online first, then went to the bookstore, sadly bookstores seem to be going away so you may want to find a store before there gone.
I'm not a fan of the manuals why I suggest books at a Boarders or Barnes, much easier reads IMO.