I feel like problematizing the economy with the prices isn't enough.
We shold have in mind most of the events are aimed mostly to AFK drillers and this benefits the wealthiest overall (they are the ones that already have the pets, WT or 300 items and DA necessary to drill efficiently), as Haz noted, only that I'd want to add the fact that it's also the wealthiest irl the ones that can multiclient more, have more time to play, and besides they may be able to recharge MS points.
At the same time, new/unexperienced/poor players have it way harder since they'd need to either spend hours/days drilling or saving for a driller pet (of course, they're new so hunting is also hard for them).
And there's also several people that naturalized these kind of events and are now spoiled and always expecting for more, plus it makes the players overall actually play the game a lot less, AFK drill leveling, getting items working a lot less (like spamming brooms to get Uniques or getting Amadas and Imperian Sets without having ever been to Harkon), and getting fuses like crazy to the point there aren't collectibles anymore.
On top of that, there's the problem that Gustavo mentioned of the characters being unbalanced. Powers can exploit Attribute to an extent they are the first ones to clear the hardest parts of the game (CT, Ed, Koiosu, True Chronos, etc.), and Hybrid Powers are probably the best class for PvP (as far as I know, the only thing keeping them on line is Magical Soul, which, well, is pretty messed up).
I do think it's totally awesome for free players to have access to items such as enhacers and MS/Gacha/Eggshop equips that were otherwise impossible or unsafe to get in eTO, but there's a lot of work ahead to make it an actually inclusive experience.
That is, if that's the server's intention. Of course, we've been told the "for the love of the game" part but we don't really know if this server's supposed to break the continuity with the money-making ideology of NTreev/Gamerage or not.
But a key part of all this is, the staff has been juggling with server stability issues, bringing new or recycling content, handling player requests and suggestions, etc., and sure, the server's not dead yet so they must be doing something good, but as far as I can observe, there's still no efficient way for them to get in touch with all the community and promote healthy debate for a better decision making, in order to get above these kind of discussions.