Maze explanation is here.
Startbonus: 400 coins
Collections: 600 coins every 8 hours (19800) = 20200 coins.
The total does not include coins we can get from quests or dragon tv.
For Collecting times check this.
Dragons:
Enlightened Lapis -L- #1323: Path = 28900 coins
Daisy -R- #1283: Path = 750 coins
key for Crustocean on step 9 (380 coins)
Crustocean -VR- #1417: Path= 2585 + 1 key = 2965 coins
key for Swamp on step 14 (1970 coins)
Swamp -VR- #873: Path = 2605 + 2 keys = 4955 coins
key for Crested Fae on step 8 (1600 coins)
Crested Fae -E- #901: Path = 3800 + 3 keys = 7750 coins
key for Stone on step 16 (580 coins)
Stone -E- #1125: Path = 4035 + 4 keys = 8565 coins
key for Fuel on step 16 (2590 coins)
Fuel -E- #1231: Path = 6525 + 5 keys = 13645 coins
key for Predator X on step 14 (1885 coins)
Predator X -E- #1415: Path = 6700 + 6 keys = 15705 coins
key for Hero on step 21 (5525 coins)
Hero -L- #578: Path 10440 + 7 keys = 24970 coins
Time limited:
17 - 19 - Mime -R- #1063: Path = 7850 coins; This path has food.
19 - 21 - Illustrious Ruby -E- #1326: Path = 2590 coins; This path has puzzle moves.
21 - 23 - Maraca -E- #1266: Path = 5300 coins; This path has flight stamps.
23 - 25 - TheDooo -L- #: Path = 9500 coins.
23 - 26 - Cyclone Genie -L- #: Path = 9895 coins; This path has joker orbs.
We can also get Terra and Sea Shards from Terra and Sea Chests for the new Terra-Sea Collection.