However, I'm somewhat uncomfortable with the request for donations in combination with these offers.
I find that to be a very weird argument, really.
Why is it problematic to offer to pay to help support something as well as have a regular payment? One time donations or monthly recurring ones that gives you small perks.
Many non-profit organisations* have such things, and En World won't be making any profit - we hope that it'll be able to pay Morrus for his work.
I have no idea what form of organisation EN World is, or will be, but it won't be a new WotC - at least not for quite a while and quite a few changes.
I don't know how it works, but I suppose that if EN World became a NPO it would be tax exempt in the US, right? (I have really no idea how that works, in particular if it's a british NPO. It just struck me as Escape Artists (the people behind EscapePod, PseudoPod and PodCastle)
are undergoing such a change.)
* And non-profit organisations aren't just 'charities'. It's basically a form of company that delivers no profit to it's owners. (But like all companies it may, hopefully, pay those who work for it.)
(My ignorance of US and British law may have muddled this, please excuse me in that case.)