100% clarity and extra sharpening on everything

I do this all of the time in Lightroom but generally feel guilty for doing so. I only hold off if it creates halos. Also I bump sharpening/detail to about 50%.

Opinions? Good, bad, indifferent?

It fully depends on what you're shooting and the type of look you're trying to get.

I use to bump up clarity a lot in many of my shots, but now it depends on the shot. Most portraits I leave it at 0, or go up/down slightly depending on the look I'm trying to achieve. If I want a certain area to have higher clarity I may use the adjustment brush for that... I notice going up in clarity more with non people shots depending on texture, color, lighting, contrast, everything!

I sharpen to what I feel is appropriate. I do 1:1 view in LR3.

The final output dictates my sharpening applications.

Sharpening for prints is more aggressive than sharpening for full-res file exports which is more aggressive than sharpening for the web.