Well, I oversimplified, but I see how it looks on hindsight. But my point is that the market is complicated, and net-exporter doesn't necessarily mean self-reliant.
1) Saudi produces a range, including primarily heavy / sour, but because they and their Asia customers have lax environmental standards, whatever light / sweet product coming from or through Saudi Arabia tends to be traded to a western country with strict environmental standards. Because of the US (historically) having an excess of heavy, the US could export that heavy in exchange for a lesser amount of light, and still come out ahead after taking into account cost of refining.
2) Fracking produces mostly gas and light crude, yes, but North American production until the most recent boom was mostly the moderate to heavy sour product, (North Alaska, Alberta sands, Gulf of Mexico, pre-shale Texas). The shift is causing the existing infrastructure to be repurposed in sometimes unexpected ways, from pipeline reversals (ho-ho) to underused heavy refining / cracking capacity, to changes in trading partners.
3) Re: fracking limited to US and Canada-
That's (mainly) due to cost of extraction taking into account permitting and compliance. It's a result of political policy more than technical ability or what proven reserves are available.
Other countries either: 1) don't need to use new fracking methods, as it's cheaper to use traditional extraction methods, or 2) don't use new fracking methods because they're regulated to the same extent (or more) as traditional extraction methods, which still makes it relatively cost prohibitive. The US and Canada just happen to be in a regulatory "sweet spot" where new-style fracking makes economic sense.