As to your first question,

This is a bit of a primer on tires, but here we go!

The rubber used in tires varies greatly, The harder the rubber the longer the tire wear in general. That is why the Michelin get a consistent 50,000 plus miles, it has a harder rubber than most tires, A Grade. But they still have a respectable B grade in traction!

That said, your traction grade is often reduced with wear improvement. (When you look for new tires you will see that the better the wear life grade, the lower the traction grade. For “great tires” the trick is to find the best in both categories! Don’t be fooled by longer tire life in a MB! Your grandmother is not going to be driving it!

When warm your tires have better grip than when cold! The rubber softens a bit! When you enter the garage on your return the tires are warmer and trying to grip better, thus some squeal if you are asking more than the rubber can give! It is slipping a bit while gripping better. Often more pronounced on concrete than asphalt! )

When they are cold on your leaving they are still slipping but with less grip and they don't cry about it as much!

In warm weather the grip is also better than in extreme cold weather! Too a point, when really hot, the tire rubber can be too soft for the demand and you loose traction and if in a high speed curve, slide!

As for the second question the problem may be in the shaft and not the wheel area, can you clearly identify the origin of the rub? Remove the plastic cowl above the turn signal arms if you can on your vehicle and see if the sound is louder. It may help you find it, if that is possible. Several devices ride on the column shaft, like the turn signal indicator return guide. (This causes the turn signal to pop back!) And your Horn electrical contact transfer. If you have air bags use caution poking around in here! Something there may need some lube!

trants4md
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85 500SEL
80 Leland TR7 Convertible
And Some American Stuff
94 Dodge Ram
93 Chev Lumina APV
79-81-83 Forzda