Should do . .try it out . . I'm sure I've done this. V4 is not discriminating - it can't/mustn't be. If it was it would be a little silly - yeah? As you know you can set project properties PAL or NTSC. Maybe you should keep an eye on how you finally use the particular veggie. But, these sample veggies are just that. They are like tutorials, allowing you to have those, "Oh, is THAT how you do it!!" moments - yeah?
I copy the best and ditch the rest. Yes, frame rates are different, frame sizes are different and maybe other stuff too. But don't be scared - if you are, you haven't said you are, my interpretation - download a veggie and try it out. Yes, it may "kick" your project prefs into NTSC - but try altering these back to PAL, if you are in fact a PALie - like me.
I'm a PALie. The one thing that you must remember is that any "substitue" media, set for PAL will be distorted by the NTSC format - apart from that I can't see a problem. As I said I use these veg examples as "How To's" rather than using them "off-the-peg".