My thoughts on the progression:
On the heroic side, you're expected to start with the PQs, work up through the DoV instances (Tower first, then Velketor's, then Kael), and finally have the gems from Kael to get you into Ry'gorr armor. That'll let you get into the Drunder instances, which'll get you the Drunder crafted armor. You'll also be in a position to run the Tower x2 raid zone, which'll get you good jewelry.
On the raid side, Ry'gorr armor and Tower x2 jewelry is enough to let you start raiding the DoV x4 zones. You're expected to work up through the 3 zones in order of difficulty, and the normal-mode DoV x4 armor and jewelry gives you enough to start on the Drunder x4 zones. The armor and jewelry from those in turn is enough to get you into the Plane of War x4.
There's two crossover points from heroic content into x4 raid content. When you get Ry'gorr armor and Tower x2 jewelry, you can jump to the x4 content at the start of the DoV zones. Once you're in the x4 content, you can go from the end of the DoV x4 zones to the start of the Drunder x4 zones and from those into PoW x4. When you get Drunder armor, you have enough to jump over to start the Drunder x4 zones. The Drunder x2 zone also gives armor that's just a hair below normal-mode DoV x4 armor, so it makes a good alternative to either Drunder crafted armor or normal-mode DoV x4 armor.
Notice here that there's no way to skip progression. If you expect to skip the DoV x4 content and jump directly to the latest Drunder or PoW content, it won't happen. And if you expect to skip directly from SF raid content to DoV, again it won't happen. There were too many complaints about a lack of content, mainly coming from people who skipped over the majority of content going directly from one expansion's raiding to the next. The devs seem to have designed things this time so you can't skip content, you need to work through all of it to gear up (or have a toon already working the higher-end raid zones who can get loot for your alts).