True. Hazlitt does not break with libertarian orthodoxy at all on the subject of free trade, and this is the one place where even great thinkers like him and Hans-Hermann Hoppe consistently fall flat. Ian Fletcher's book is in fact part of the basis for Vox Day's antipathy towards the entire edifice of free trade, and if you're interested in seeing an argument against free trade made from solid first principles, then I highly recommend reading through what Vox has written on the subject. Like me, he started out as a free-trader; and it's thanks to him that I've largely changed my mind on the subject.

I would actually strongly recommend that you not even bother with The General Theory. Instead, read Henry Hazlitt's take on the book, The Failure of the New Economics. You will be spared no small amount of time and tedium in reading Keynes's "masterpiece", with all of its density and obfuscation and bad logic. Hazlitt did the job for you by reading it and dissecting it almost literally paragraph by paragraph. And Hazlitt's work is vastly more readable.

If you must read any work by Keynes, I recommend starting instead with The Economic Consequences of the Peace. If Keynes had written only this book, and left it at that, he would have been remembered without controversy as a great economist. Unfortunately, he wrote his General Theory as well, and forever destroyed economics as a respectable profession.