Ok just back from work, let me try to catch up. Please bear with me.
The diving board analogy: not terrific but I see where you are going, however the terms that have been used in the various warnings lead me to interpret it as once you take the first rung of the ladder you must inevitably jump into the water. In other words you are already wet and just do not feel it yet. You say that is not the case so I will take your word for it though it may leave you with a faction level you do not wish to have and no ability to change it for the better. That is an extreme case and unlikely to remain true forever but may if nobody complains about it and it is otherwise unnoticed. Perhaps that is the intention and what you mean by no redemption.
Now protection from bugs: bugs are unforeseen adverse effects of coding, yet you claim that the best writers will protect us. I appreciate your confidence but I do not share it, you can have the best written quests in the world but it takes very little, a misplaced semicolon or bracket in the actual coding to cause a bug. Source code is only extremely rarely bug free upon first implementation, and often it does not become apparent until tested under production load. They are particularly hard to avoid when the code is disorganized and cobbled together as I suspect much of PS's code is, no disrespect intended. I do hope you have daily backups of the database as well as weekly and monthly as that is about the best protection you will get, the ability to restore a character that has been deleted due to a bug in a timely manner.
I find it just a little patronizing to tell me to have faith when I implore you to proceed with extreme caution. If it is not apparent that is my basic message. When I raise objections they are the things I can see might go wrong, when I offer suggestions they are the things I hope might help. Nuff said about that, for now.
And another thing: Imagine you play some sort of paladin, do a quest that gives you access to a dark mage laboratory but leaves a "mark on your soul" - priests or other similarly aligned characters would be able to see it and deny you access to a holy area.
You mean sort of like stealing candlesticks from the Laanx temple? Seems redemption is available for that. What if you gained the access to the lab in order to destroy it? I suppose it would depend on what you had to do to gain the access, but surely atonement is possible in most good aligned religions, isn't it? It doesn't take much to become evil but if there is no such thing as redemption in PS what good are the religions? Do the Gods rule with fear and offer no hope?
I really do not like the cross breeding between quests and events. What am I supposed to do if I happen to get a quest that requires me to participate in an event which never happens when I am on-line? I suppose I could buy an event item from someone else but the price is likely to be far higher than any potential reward from the quest. If the quest require I take some particular action in the associated event I am just SOL! (out of luck), hopefully I will be able to delete the quest without too many problems arising.
The only difference between an NPC (/GMs) and players right now is that only NPCs and GMs can "see the mark", players cannot.
I looked for the context that would make this true but could not find anything explictly connected. I suppose implicitly it is 'in relation to the ability to determine whether a player will suffer horrendously' "the only difference... ...players cannot." Can we expect any of the npcs to be subjected to deletion due to their crimes?
Well, that will thicken the porridge.