Would it be safe to drop the g 1.5 without scrapping the kit etc?

I don't think the stock body kit hangs lower than the stock car without it.. it just covers the otherwise black pieces, making it appear to be lower.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

It is lower with the body kit on. by how much i'm not sure, but it looks to be about 3/4 inch. If your lowering your G35 an additional 1.5", it will probably cause scrapping when driving over big speed bumps, steep driveways, etc... normal driving you should be ok tho.

So if you don't mind going into driveway approaches sideways and the same for speed bumps, then go for it...

Ivory Pearl - 6MT - Sedan