Yes, you can achieve pretty much everything Looks does without the plug-in. It's just going to take more work and may require things like extra-precompositions, multiple layer duplicates, extensive use of blending modes, channel-based mattes for thresholds, masking. Of course it will also require a keen eye, good knowledge of AE's effects and tools and experience.
Awesome, thank you for responding. I'll study Magic Bullet and do some more experimenting in After Effects.
Given enough time and a thorough knowledge of the inner workings of AE I do not think there is any effect by any third-party that you could not replicate, with the exception of Element 3-D, 3-D stuff from Zacks, Boris FX and a couple of other 3-D plug-ins. using the native plug-ins that come with AE. You just need a lot, and for many an awful lot of time and a very deep knowledge of visual effects and the use of all native effects. The reason that Shine from Trapcode is in almost everybody's toolbox is that it takes several layers and many minutes just to get to the point that you arrive at when you first apply Shine.