Need Crystal Malt for head retention w/ Extract?

I am working on a recipe for a blonde ale using Pale LME. I have read that pale LME is made from crystal malt and obviously crystal malt is used for head retention and body. So, if my base extract is pale LME, do I need crystal malt as well, or will the extract already have the necessary properties necessary for the head retention and body?

Also, how do I know which grains can be used beneficially by steeping as 'specialty grains' and which ones require mashing?

I wasn't sure myself so I did some digging and this article:

http://byo.com/hops/item/621-fabulous-foam

seems to indicate that the head-retaining properties are lost during the processing of Malt Extract.

Sounds like Carapils will work well for head retention, though Crystal is supposed to as well.

https://www.homebrewtalk.com/showthread.php?t=206714

I don't think they're lost in the extract production process. I've made a lot of beers with LME & DME & no grains & got good head. It's all in the dissolved proteins to form the head, which is driven by the carbonation in the glass. Here's a couple pics of my AE beers as evidence;
Buckeye Burton ale;

Sunset Gold PA;

& my 1st, Cooper's OS lager;

I've never had a head retention problem yet, but I've very seldom made an extract only batch, most have had steeping grains so I wasn't sure what the deal would be for a batch without some steeping grains.