You can lasso them on the timeline, right-click and choose "remove attributes..." Then, make sure "plugins" is checked, and click "apply."
After that, I will need to apply some effects to multiple tracks at once, but I believe this can be done by selecting all tracks and dragging and dropping the effect on them.
Yes, you can do that. You can also apply effects to a whole track, which often saves a lot of mouse clicks, and helps you stay consistent. There's a row of tiny plus signs on the mixer channel strips labeled "effects" where you go to do that. It's also possible to group multiple tracks together, send that through a submix, and apply effects to the whole group at once. So you could affect dialogue uniformly, for instance.