I'd be fine for paid perks such as different themes or a badge like others have said before, but I am absolutely against paid perks that prioritize players on this site, allow getting/incubating/gendering an egg/dragon to be easier for paid versus unpaid on this site.
And an in-game currency is also an absolute no-no, whether it can be bought with real money or not. Hoarding money and dragons, hyperinflation (especially if the idea to fix the hoarding is just to make more money), "how much can I get for this dragon?" bid wars and contests among many other issues that would arise because of the new economy. It would be a mess. There are just too many problems with using a currency for it to be a valid option.
Showing support through donating, buying an ad-free membership, or buying something from the shop (which also helps support the artist so two birds one stone) is completely adequate.
As for internet connection speeds, even with a slower speed you can still get decent dragons through the AP or here on the forums. It's all about being in the right place at the right time.