Some combos (that register as actual combos in training mode) I found when playing around today:
-Uthrow, Usmash. Only at very low percentage (Max 9% vs Mario, but only at 8% consistently), can be vectored out of (or misses unless at 0%) unless you dash first. Fair or Uair also works instead at slightly higher percentages. (25/19/22% damage)
-Bthrow, (Almost) instant Dash Attack. At 0% it worked on Mario and Bowser, but not Pit. Can string into Fair afterwards by dashing into jump, but it's not a combo. (17% damage)
-Point blank Dash Attack, Utilt, Utilt. They can proably vector out of the 2nd utilt though. Can pursuit with Uair, but it's not a combo. (10-23% damage, depending on if you get 1 or 2 utilts, and how many hits you get, which varies with how high % they have)
-Close-hitting Dash Attack, Fair. This is an actual combo from 44% to 74% (On Mario)(40% is also around where utilt starts hitting only once or not at all), requires you to do Fair instantly from the ground though (Slightly delayed on higher %), and not short hop. On higher percentages you can actually combo a 2nd Fair after the first one if they vector poorly, otherwise it's still your best pursuit option. (14-21% Damage)
Here's some quick combos involving these:
-(At 0%) SH late-hitting Nair, Dash Attack, Uair (23%)
-(At 0%) SH late-hitting Nair, Grab, Uthrow, dash Usmash (33%)(Doesn't say grab combos, but it's faster than Fsmash (which combos), so I assume it's only an issue with the combo counter in training mode)
-(At 40%) Tripping Dtilt, Dash Attack, Fair (19%)
-(At 0%) Tripping Dtilt, Grab, Bthrow, Dash Attack (22%)