I think donations are fine because I do think even basic admin work, paying money for a skin (around 200 or more), building on lore and whatnot is a lot of work. However, donations should always be voluntary and members should never have to feel pressured or obligated to do so. Moreover, there needs to be a lot of transparency in where the money they are donating is going, including receipts.

That being said, accepting donations from members means feeling responsibility towards them- in a way, I can understand a site that doesn't want to take donations because staff might not want to feel like they owe the paying members some kind of in-character rewards or allowing them to influence site decisions.

This is a tricky line for me, but I lean towards absolutely no IC rewards (that aren't just for flavor, like a badge, a discord color, etc.) for the members even if they donate. The second something is accepted for that, it sets a precedence that monetary gain is the equivalent/is more important than effort... I don't know if this is the message that roleplaying sites want to put through to their member base. You nailed it when you said it's about preserving the community's essence and principles-- roleplay has largely been here as a medium for enjoyment without making it capitalistic in their monetary gain. I believe that once real money gets involved in site plot, character growth, etc. things will inevitably turn ugly.