Webbrowser Refreshers- Freezerate?

I know of a refresher, not related to neopets, that basically refreshes as many pages as you want at variables of 7,10,15,20,etc seconds (whatever you want). You open tabs of internet explorer basically, and it actually refreshes the pages for you (no Inet, nothing virtual, just basic IE browsers with auto refresh). What would be the freeze rate on such a refresher as this?

Also, I've always wondered how those people with shops full of 50+ of each lab map piece get their stocks. Anyone know?

Also, do you guys think it would be safe to refresh 5 pages every 10 seconds, or would even that be detectable?