I believe I found the source of the crashes. It is, I think, because all the template files are in NTSC and complex multi-level, multi-timeline work with PAL project settings is too much for the system.
I converted all the files from NTSC to PAL, starting at the most distant sub-timeline, working my way back to the main timeline. It became as steady as a rock. It's a pity they didn't offer the templates in PAL, as well as NTSC.
