Walter wasn't forcing Jesse into taking revenge by poisoning Brock, and he wasn't forcing Hank into starting up his rogue investigation.
Uh, yeah he did. First by being related to him and operating under his nose for so long, then by threatening him in the garage, and finally by blackmailing him with the video.
If Hank had gone directly to the DEA with the circumstantial evidence he had, he would have been immediately taken off the case at best, and suspended at worst. Either way, any chance for advancement he would have had would have been long gone. His career was over no matter what because the drug kingpin they had been searching for turned out to be his brother-in-law and had been operating right under his nose the whole time. So if Hank was going to go down anyway, he needed more concrete evidence than putting two-and-two together with the book. Which is why he kept everything to himself (and later Gomez) until he found some hard evidence, so he could continue working the case, because he was in the best position to bring Walt down. He spelled this out to Marie earlier in the season.
Then Walt threatened him (and by extension Marie) in the garage, which gave Hank further reason for caution. And finally, Walt made the video implicating Hank in the crimes, which made it entirely impossible for Hank to go directly to the DEA without solid evidence that Walt was the kingpin.
Hank could have chosen to go to the DEA at first, but it probably would have meant that Walt got away with it and it definitely would have ruined Hank's career, so it's not like he wasn't backed into a corner by Walt. Then afterward, there's no question that Walt forced his hand with the threat and blackmailing.
Anyway, as far as the episode goes, everything I've wanted to say has already been covered. Just an amazing, heartwrenching episode from start to finish, full of plenty of incidents that would qualify for amazing show finale moments on their own, yet here they're all in one episode and the show's not even over yet. Hank going out with style, Walt's cruelty toward Jesse with the Jane taunt, the knife fight and the kidnapping of the baby, Walt's phone call, Jesse's utter despair at being caught and imprisoned... Just astounding drama.