Volcano's launch is only slightly weaker than TTD's. The main reason why people think the launch is "intense" is because of the speed, which apparently overrules actual force. Really it's just nothing more than a large number for speed and height and general mehness everywhere else.
4 full seconds which is roughly about 1.37 G's. Verbolten pulls about 1 G in its second launch and rides like Blue Fire Megacoaster @ Europa can pull about 1.2 Gs in their launches. It's not really much of a noticable difference, yet apparently people can "feel" that difference. If I remember right Hypersonic pulled 2 Gs on its launch.
Wild Mouses pull more force than all of these launches by the way.
Not the slightest clue, I can't find any mention to how long its launch track is and how much time it takes to get to 70 mph.
EDIT: By the way, force isn't speed in general. It's how much time it takes to get to that speed. The less time taken to get to a set speed the more force. The more speed in the same amount of time is more force, too. So going from 0-60 in 2 seconds is more forceful than 0-60 in 4.