Consequences of High Wyrd
The books do a very good, if at times scattered and confusing, job of explaining the many and varied consequences of having High Wyrd. We won't be duplicating all of that information here, but rather giving examples of how the gameworld will be treating it.
Once you pass that boundary and veer toward Wyrd 6, you are officially more fae than human. Your emotions and impulses are more intense, your grasp on human morality less so. Clarity is not morality. You can have a perfectly lovely grasp on the differences between Faerie and the mortal realm and still be increasingly puzzled by why you shouldn't trade your grandmother's treasured spoon collection for a case of diamond necklaces (what, they're equally valuable, aren't they?) or you shouldn't use a broken Devotee to go oblige your every whim. Your power is increasingly driving you toward caprices, to act more like your Keeper, and unless you are very, very careful not to cross the lines, people will notice.
You are addicted, fixated, on harvesting Glamour, however well you hide it. You may compensate for this by wandering the streets and plucking little bits here, little bits there; by gathering a harem of admirers and evoking strong emotions with performances; by becoming a monster worthy of news reels whom nobody can catch -- the options are as endless as your imagination.
People in Fort Brunsett are likely to think you're just an oddball or an eccentric. This won't have much effect beyond social reactions there. People in Tamarack Falls? Yeah. They have lived among Changelings for centuries. The folks there know what it means when someone starts acting woolly. They'll be more wary of you, less trusting, and unlike most towns, they do know all about Cold Iron.
Speaking of iron... No, you are not hurt by it. Only True Fae take special damage from Cold Iron. Your aversion to it, if you decide to have one, would more likely be due to the fact that you ARE a Glamour addict. You are more fae than not, and you use magic for trifling daily tasks. Admirers are wonderful -- add totally unnecessary, but artistic grace to your silk-swishing step. Wake up with baggy eyes? Reshape your face until it's even more perfect than it was to begin with. Iron is not affected by faerie magics, and will pass right through them. It spoils your fun, but it doesn't hurt you.
Your real weaknesses are your frailties.
For Brunsettians, again, you probably don't have to worry. Most NPCs haven't the faintest idea that changelings even exist. For folks up in Tamarack Falls... they do. They know all about faeries having strange limitations. It may be comical what they expect ("What? You mean your magic CAN cross running water?!"), but expect NPCs to at least know that limits happen, albeit not any reason why, or what, or how.
We're not talking about "can people see you" here. This is about how much you stand out in a crowd of other changelings, and the answer is "a lot" unless you put effort into assuring otherwise.
Mortals will notice weird vibes around you. Sometimes, your Mask fails; decide early on a few quirks people might see/feel when they look at/touch you now and again.
Most importantly, True Fae will pay ever so special attention to any rumours about you, since you are starting to become a mighty interesting thing. Whether they want a powerful pet, an ally or a useful, all-unknowing pawn to move around some great metaphysical board is up to their own decisions, but be aware that hobs, especially, will take note of you wherever you go. Some may be loyal friends, some may be afraid, but others may go tattling to their masters.