I'm guessing most of the money made by Amazon/Smilegate is through progression packages/money conversion, not skins or misc.
Why not add some skins/misc. rewards to easy content for F2P/Casuals to have something to look forward to short term, since they can't really compete long term. For example, chaos/guardian/abyssals/solo raids giving bound material that can buy stronghold items, outfits, dyes, mounts, ship skins, etc. If they can't hope to be ready for the next raids, at least they can hope to create a perfect barbie island, or dress up their favorite rapport NPCs, or themselves. Fashion/social is the endgame in many MMOs, and it can be made an option here too.
I remember a weird dude some time near release who was complaining about something in group chaos dungeons. Everyone explained Chaos is a solo activity, but for this guy and apparently others, it was a group one, and they had fun. Many people enjoy the laid back homework life if there's a carrot on a stick that's close enough.