The interpretation you suggest putting on the commerce clause make a mockery of the whole idea of limited government. Your intepretation leaves the federal government to regulate virtually every facet of our lives. This was not the understanding that the founders had of the authority of the federal government.
One of the rules of statutory construction is that you should interpret statutes in light of the problems the statute sought to address. There were two problems that the commerce clause sought to address.
First, some states were putting tarriffs on goods from other states. Second, some states refused to allow goods from another state entry into their borders. These two issues caused significant problems with trade. These problems were among the main reasons the Constitutional Convention was held.
Reading the commerce clause in light of the problems to be addressed, and in light of the founder's understanding that they were instituting a government of limited authority, you can readily see that the interpretation you suggest is inappropriate.
From The United States v. the William (28 Fed. Cas. 614, no. 16,700 D.Mass. 1808):
Furthermore, the power to regulate commerce is not to be confined to the adoption of measures, exclusively beneficial to commerce itself, or tending to its advancement; but, in our national system, as in all modern sovereignties, it is also to be considered as an instrument for other purposes of general policy and interest. The mode of its management is a consideration of great delicacy and importance; but, the national right, or power, under the constitution, to adapt regulations of commerce to other purposes, than the mere advancement of commerce, appears to me unquestionable.
Corfield v. Coryell (6 Fed. Cas. 546, no. 3,230 C.C.E.D.Pa. 1823)
Commerce with foreign nations, and among the several states, can mean nothing more than intercourse with those nations, and among those states, for purposes of trade, be the object of the trade what it may; and this intercourse must include all the means by which it can be carried on...
Justice Marshall in Brown v. Maryland (12 Wheat. 419 1827):
It may be doubted whether any of the evils proceeding from the feebleness of the federal government contributed more to that great revolution which introduced the present system, than the deep and general conviction that commerce ought to be regulated by Congress. It is not, therefore, matter of surprise, that the grant should be as extensive as the mischief, and should comprehend all foreign commerce and all commerce among the states. To construe the power so as to impair its efficacy, would tend to defeat an object, in the attainment of which the American public took, and justly took, that strong interest which arose from a full conviction of its necessity.
This is not the "destruction of limited government." One of the enumerated powers of Congress is the power to regulate commerce between the states. The power has a clear limit: there is no power granted to Congress to regulate the commerce that takes place within the borders of a state. Most cases in which the Congressional power to regulate commerce has been limited by the Courts involve the distinction between intra- and inter-state commerce, as this article indicates.
The general rule was clearly articulated in Carter v. Carter Coal Co., 298 U.S. 238, 303, 56 S.Ct. 855 (1936):
One who produces or manufactures a commodity, subsequently sold and shipped by him in interstate commerce, whether such sale and shipment were originally intended or not, has engaged in two distinct and separate activities. So far as he produces or manufactures a commodity, his business is purely local. So far as he sells and ships, or contracts to sell and ship, the commodity to customers in another state, he engages in interstate commerce. In respect to the former, he is subject only to regulation by the state; in respect to the latter, to regulation only by the federal government.
I have not found cases where the commerce clause was interpreted as having limits on the ends to which interstate commerce could be regulated.
The problems to which you refer were of course in mind when the Framers met, but in fact they didn't write: "No state shall lay tarrifs on goods imported from any other state; nor prohibit the importation of goods from any other state." They explicitly assigned to the general government a power to regulate commerce between the states, stated in general terms, with no specification as to its objects or purposes.
Most of the abuse of the commerce clause has been through strained definitions of interstate commerce. In the present case, it seems me quite obvious that internet sales are interstate commerce. I would oppose as bad policy most regulation of such sales, but not on constitutional grounds.
Nor does this interpretation detract from any powers reserved to the state. It does not propose the federal prohibition of the making of virtual child porn, which, according to the rule cited above, is a matter for state action. It suggests that it would be constitutional to prohibit offering such images for sale across state or national borders.
Furthermore, the internet poses new problems of regulation which the 18th century did not foresee. However, the Framers did not give the commerce clause a narrow guage, precisely because they were not only concerned with a specific set of contemporary issues, but because they recognized that interstate commerce would inevitably present continual complications which required federal oversight. As Madison wrote to Monroe in 1785, as the defects of the Articles were becoming clear:
Viewing in the abstract the question whether the power of regulating trade, to a certain degree at least, ought to be vested in Congress, it appears to me not to admit of a doubt, but that it should be decided in the affirmative. If it be necessary to regulate trade at all, it surely is necessary to lodge the power, where trade can be regulated with effect, and experience has confirmed what reason foresaw, that it can never be so regulated by the States acting in their separate capacities. They can no more exercise this power separately, than they could separately carry on war, or separately form treaties of alliance or Commerce. The nature of the thing therefore proves the former power, no less than the latter, to be within the reason of the foederal Constitution.
Your reading seems to me to be controlled by your idea of what a "limited government" ought to be, rather than by a real examination of original meaning.