Nutshell: Player choice, but most lean to getting the Skill Point.
In general, for most players, giving the Crown to Toll is considered the better option. It gives a Skill Point bonus, adds a more complete narrative of the history of the continent, and allows the Bishop to live.
That being said, the Bishops Ring is a top tier item. Strong Death Protection, defense and one of the few items to give a +2 to a stat. For Clerics and Mages, that +2 PERS turns into a decent amount of magic. It also gives a nice reputation bonus, for those that need it in game, or those that are competing for a total score game.
The drawback to ring is that it's use is best limited when fighting enemies with death damage, or no elemental damage. Against other elements, you're likely going to swap out for rings with a matching elemental resistance. You can also get a +2 PERS item later in the game, if you complete the game peacefully. Additionally, by the time you can get the ring, you've likely already killed off the worst of the liches, and have completed the Pits, the two places that benefit the most from death protection.
The area with the most death damage is The Pit, ruled by The Void Lord. So if you beat that, than you are good to take on any other death damage area. If you are really looking to max out death protection, The Ring of Unlife is notable.
My Adaon have one ring of unlife, but iron golem as shield and high staff damage are enough for me. Just I wan't to first clear lambar cave or mercian crypt(my main target is nr 2, with very strong death staff), eventually I will second time complete Castle Storme. Later I defeat Void Lord, perhaps then I take Ring of Unlife from Adaon, I without any companion, as Mage Summoner clear some of hardest dungeons in game. I have only one problem, with Mercian Crypt. Undead from this trap always block me before the iron golem can block them and protect me. I even tried with a companion, but they was too many.
For the Mercian Royal Crypt ambush trap:
Have strong death protection (use Death Resistance if needed)
Have Companion with strong death protection
Take out the healer that hides in the back (Skeleton Evoker?)
Given your level, that should work.
If you're still getting over whelmed, try using a speed potion, and running away (or in a circle), till the enemies attack your summon / companion).
It can be brutal ambush trap, but it should be doable.
This is a hard choice for me too. I'm ironmaning with mage, so that ring would make some stuff much easier. Usually doing the right thing has the better drop, sadly that's not the case this time. I think I'll get the ring, it will be much too helpful and Gods are usually detrimental overall so I don't feel too bad about it.
I am not sure turning the crown into Tol is worth the 1 skill point which is half a level. The ring is worth 9 trait points in my build or 3 levels. Yes, trait points are easier to find outside of leveling, but as a rogue I can go from 8 to 9 agility while wearing the ring for 5 personality. The 2 personality neck makes me stunnable. As a rogue dps out weighs resistances, faster killing equals less damage taken. Killing things in cycle of evasion to stay closer to full health/mana for bosses is a good thing.