If radiusing the ground electrode was a good idea, NGK would do it. It isn't a bad idea, but it won't contribute to anything.
Idexing the spark plugs has been discussed for years, and no one is really capable of saying whether the gap should face the intake valve, the squish zone, the piston, the whatever. The jury is still out on that one too.
Extended tip plugs, wide heat range plugs, are all good developments. Multiple electrode plugs have been used for years in aircraft engines, and for some reason many think they are a good idea in cars. They probably aren't.
Check out www.ngksparkplugs.com and read up, or find a copy of the Bosch Engine Electrical text, which may very well be one of the best books on the subject.