There used to be some good threads about crank dampers here, but it appears they were lost in
The Great SHOForum Database Burp of 2008.
It isn't about crank pulley strength, it's about damping crankshaft torsional whip. The OEM crank pulley is a harmonic damper, it has two masses connected together by a layer of elastomer (rubber).
And if anybody calls the crank pulley a "harmonic balancer", I going to ask Beth to ban your ass. 
Crankshafts aren't as stiff as you might think, the input torque from the individual cylinder firings can axially distort the crank, and at certain RPM's and power levels, the distortion can turn into oscillation or torsional whip, and if the oscillation gets large enough, the crank will break.
The OEM crank damper is designed to damp the crank oscillations by turning them into heat by trying to shear the rubber layer between between the two masses of the crank pulley.
If you replace the crank damper with a solid pulley on an engine with relatively stock power output, you probably aren't at great risk for crank breakage. On a boosted engine where you've doubled or perhaps near-tripled the stock power output, you're asking for a broken crank, and in the distant SHO past, there have been cases of broken cranks on boosted engines with solid crank pulleys.
OTOH, there have been some high output SHO engines with solid crank pulleys that haven't broken cranks.
Unfortunately, the data-set is very small. I'm just making the information available, how you use it is your business.
And FWIW, the Aluminum flywheel problem is less about thermal capacity than it is about stiffness and materials compatibility. The aftermarket (SHOShop) billet steel and Aluminum flywheel blanks were cut on the same CNC program, which means that the Aluminum FW had at least 30% less stiffness than the steel unit. The stiffness problem comes about with the double diaphragm clutches that need to be used with the high output boosted engines: The Aluminum FW deflects too much to be effective with a DD clutch. Additionally, the steel inserts in the Aluminum FW's are not terribly compatible with the aggressive friction materials that tended to get used with these FW's. The thermal issue with the Aluminum FW's is really tertiary, IMO, it's primarily related to the low mass of the steel insert, and having all that Aluminum behind it really isn't all that helpful.
If you're building a boosted engine, a billet steel FW is just a better all-around choice for stiffness, friction material compatibility, and lastly, thermal capacity.
Cheers,
