First of all, about base upgrades I'll let other speak... it's been quite a while since I finished the whole tree. But I'd say upgrade merchant, gem defense, skull bonus, key capacity/regeneration. Door locks and gold mine should be the last ones.
It definitely takes ages to upgrade the throne, that's why you should be always running rituals with low gems from mines, and when one is stolen just replace it right away. It will take a while but I suggest you not to care about gem score much, but focus on the key upgrades ( throne and traps). Once you get to level 51, you are thrown in the big pool of players and everyone with max throne and upgrades will be able to raid you, so you should arrive there kinda " prepared".
For traps, same story. You should always be upgrading one, and try to keep all around the same level if you can do so ( level 40 saw level 10 redguard level 10 cannon is way worse than having all around 21-22, for example). In some dungeons you can use the upgrade cloud very effectively to cover the jump points, in fact in some dungeons a cloud is much better than the original trap .
Hope this helped a bit,
feel free to pm me should you have further questions or send me a message on telegram, the community there is much larger than the forum which is quite dead unfortunately.
Hello, I track maze spins together with a "bunch" of other stuff.
Out of 355 tries, I won the 50 orbs 36 times ( I never respin). I don't track tears unfortunately.
So the odd, atleast for orbs, seems to be exactly the 10% shown.