The ebrake is the answer to the 1st and 2nd situations...1st-take the corner leading to the straight @ the inside apex faster than u normally would, and yank and hold the ebrake so the rear slides along the outside of the straight(so much easier if their are rumble strips there), until you can clear the 2nd corner(also a good oppurtunity to practice wall taps) and this method works best w/ front biased brakes as you can use slight braking to adjust your angle while the ebrake is held...
2nd scenario presents the safest way to practice reverse entries because in roundabouts(especially the one on Autumn Ring, downhill) its hard to have too much angle because the turn keeps going..I like a nice scandinavian flick to the outside and then to hold the ebrake and let my momentum and gravity carry me down(while steering of course) and to keep the revs up. So that when ebrake is released, you're just going into a nice manageable drift..
Its all about going too fast and using the ebrake(as well as some of the gangsta ish I pull on my dfgt w/ no external handbrake, its amazing how well people can compensate, i'd probably have a chance at being a pro drifter if I found a way to wire the clutch engagement and ebrake in to a lil "O" on the right side of my steering wheel...lol)