Good idea for a thread, we usually don't hear that much about DS9 inconsistencies but of course they exist.
Then again, what we'd call an 'inconsistency' in other Trek series, in many cases can simply be shrugged off as 'non-linear' in DS9
I wanted to bring up the Vorta telekinetic abilities problem, but of course that already was done on the first page
The first Vorta they meet seems a fugitive, apparently a victim of the Dominion. Later the Federation thinks the Vorta are the leaders of the Dominion, and only after that they learn the Vorta are in fact the middle men. It might be that the Dominion projects that kind of misinformation purposely as a weapon, too - making 'the enemy' believe Dominion species either have
less or
more powers than they actually have. In that sense, specialised Vorta such as Eris would fit in their strategy.
A changeling might have made for a more effective spy at that stage when no-one even knew about the existence of the Founders, but it seems they didn't even want to run the risk of handing out
that information too early.
They even mask irrelevant details such as the age of the Dominion. Is it 10,000 years old (Weyoun 8) or did it only 'endure over 2,000 years' (Weyoun 4) (while not technically being a contradiction it seems to leave an extremely wide gap on purpose).