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...
I think the elemental chaos and primordials could fit in really well in Athas.
And cut down on the rage, please, there's no need for it. If you want old Dark Sun look for it on eBay.
I think the Vistani'll be psionically inclined humans. Combining some of the best parts of earlier such attempts. Perhaps they have an extra power point?
Campaign Cartographer gives you the full right to maps created with it.
DunDjinni doesn't, and seeing that it's mostly cut and paste of their artwork that's natural.
Most others would also be ok, as long as you don't include any copyrighted material (as usual).
As long as everybody is having fun, including you, there's nothing wrong.
But cheating... I suppose that as long as everybody knows and is ok with it, sure, go ahead.
There's also the proverbial, but underused, adage; Talk to your players.
Gargoyles as D&D monsters seem to have been of low intelligence (Int 5-7), at least since 1st ed AD&D. That puts them on par with ogres and minotaurs (though not all 4e and Dragonlance minotaurs).
I think that some connection to powerful entities sounds reasonable, though many would not worship...
Different groups have different ways to keep secrets interesting.
Try to explain to him how your group usually does.
Also point out that if the players know they can set up interesting situations with their unknowing characters.
You can also do very nice maps in ordinary image editing programs.
GIMP is a free and very good image editor.
You can also use it to cut up existing maps and pasting them together as you want them. (You should not distribute such maps without the original artist's permission, though. But for...
Start cheating back, openly.
Sorry, slip of the mind, I was thinking as a DM again.
One of my players recently got a tensider that was so crooked it wouldn't lie flat on several numbers - makes you think of Lou Zocchi!
(And no, he doesn't roll it - just keeps track of temporary hit points...
I'd be interested in adventures that aren't like WotCs - i.e. not just dungeon crawls.
(Nothing wrong with a good crawl, but a little variation is fine.)
For those who like horror fiction I can recommend this episode of PseudoPod (a weekly horror podcast). The third short story in the episode has, sort of, to do with recognizing werewolves.