> Code is speech and compelled speech violates the first amendment.

The first amendment does not blanket ban compelled speech. You can be compelled to testify against someone if granted immunity. You can be forced to take an oath or affirmation in court. I'm sure there are other examples.

> The laws about giving (not selling) tobacco to minors are state laws, not federal. There’s no interstate commerce there or here.

If multiple states have differing legislation over the same area of commerce, it can affect interstate commerce. But anyway, after Wickard v Fiilburn interstate commerce is never not implicated.

> An Ohio farmer, Roscoe Filburn, was growing wheat to feed animals on his own farm. The U.S. government had established limits on wheat production, based on the acreage owned by a farmer, to stabilize wheat prices and supplies.

> Filburn grew more than was permitted and so was ordered to pay a penalty. In response, he said that because his wheat was not sold, it could not be regulated as commerce, let alone "interstate" commerce (described in the Constitution as "Commerce ... among the several states").

> The Supreme Court disagreed: "Whether the subject of the regulation in question was 'production', 'consumption', or 'marketing' is, therefore, not material for purposes of deciding the question of federal power before us. ... But even if appellee's activity be local and though it may not be regarded as commerce, it may still, whatever its nature, be reached by Congress if it exerts a substantial economic effect on interstate commerce and this irrespective of whether such effect is what might at some earlier time have been defined as 'direct' or 'indirect'."[2]

https://en.wikipedia.org/wiki/Wickard_v._Filburn