Chance of playing in Europe: 100% (Maybe 99.999%.)
Path to Europe: Last year, I said, "In the amazingly unlikely event that they lost all further matches, there is no way Aberdeen wins enough to catch them." This year, if they lost all further matches, Aberdeen and Rangers would probably catch them. But a third-place finish would still net the Europa League. And they are still overwhelming favorites (Fivethirtyeight just says >99%) to win the league. And probably the Scottish Cup.
How happy we should be if they're in Europe: Copy/paste from last year: Very. They are the only Scottish side structured to make some noise in the Champions League.
Managerial outlook: Good, although it's not unrealistic to see Brendan Rogers being lured away.
Chance of playing in Europe: 90%
Path to Europe: Well, they can hold onto their second-place position, drop to third, drop to fourth and have Motherwell not win the Scottish Cup, or drop below fourth and win the Scottish Cup. One of those is very likely to happen.
How happy we should be if they're in Europe: Quite. Hopefully they've put the dysfunction behind them that caused an early exit from Europe last year.
Managerial outlook: Medium. Their caretaker manager has been doing okay, but maybe not well enough to land the job long-term. They need not to make another mistake.
Chance of playing in Europe: 90%
Path to Europe: See Rangers. Aberdeen is only two points behind Rangers, with a game in hand, so they are practically tied.
How happy we should be if they're in Europe: Quite. Even though they "only" got 2.5 points last year, they and Celtic are the only two Scottish sides to have more than that over the past five years.
Managerial outlook: Good. After Derek McInnes turned down Rangers, he seems to be set to stay in Aberdeen a bit longer. They've struggled somewhat in the last half of this season, but he should guide them well in Europe.
Chance of playing in Europe: 75%
Path to Europe: Stay in fourth place and Motherwell doesn't win the Scottish Cup, or move up.
How happy we should be if they're in Europe: Happy. Neil Lennon knows what he's doing; he even picked up points for Scotland two years ago with a second-tier side.
Managerial outlook: Good. Lennon is a veteran, but his name has not come up in coaching searches elsewhere.
Chance of playing in Europe: 30%
Path to Europe: Move up to fourth, Motherwell doesn't win the Cup or move up to third.
How happy we should be if they're in Europe: Not very. Steve Clarke has done an amazing job with them this season, but they don't have the resources to compete in Europe.
Managerial outlook: Good. Clarke has done an amazing turnaround, but I would not be surprised to see him get snapped up by a bigger club (e.g. Rangers).
Chance of playing in Europe: 10%
Path to Europe: Win the Cup.
How happy we should be if they're in Europe: Not at all. Not only do they not have the resources, they are currently sitting seventh in the Premiership, which means a Cup win will probably be a bit of a fluke.
Managerial outlook: I don't know anything about it.
Hearts (and everybody else)
Chance of playing in Europe: 5%
Path to Europe: Turn on the afterburners and end up in fourth at the end of the season.
How happy we should be if they're in Europe: Not very. Though Hearts has resources, they disappointed in the league since returning to the top flight, and they have been (wisely) limiting their on-pitch spending while they renovate their stadium.
Managerial outlook: Mostly good. Craig Levein is doing pretty well in his second stint as Hearts manager -- he did end Celtic's unbeaten streak. On the other hand, he let Kilmarnock pass them for fourth.