IBU calculation questions, please help!

Okay, so I used Beersmith 2 and converted this Flower Power IPA clone over to extract.

It's very interesting that if I add the LME at the beginning of the boil I need MORE hops than the all grain recipe. If I add it at the end of the boil I need way way less about half......

So what this is telling me is that the more sugar that's in your boil water the less the hops are utilized? Is this correct?

So if you just boiled straight water you would get huge amounts of hop utilization. More fermentables = less utilization. Right?

I want to do this tomorrow and I'm still scratching my head.

If you add lme later in the boil, bitterness increases. I have done it when I extract brewed on purpose to increase bitterness. It does not increase harshness, but I still wouldn't do it in any beer that is not intended to be "hoppy", like an ipa. It does keep the beer lighter in color as well, the lme doesn't have as much time to darken in the boil.