I played AQW back when I was 11 and stopped around 2011 or 12 and recently came back in April after mass dropping games like Warframe and GW2. I've recently made it way past where I originally stopped with a new account and remembered why I loved this game back when I was a kid.
In games I love freedom of any type may it be the ability to customize your character or how do I want to play the game. A good example of both of these would be Dragon's Dogma, not only does it offer great customization in terms of appearance but each class is distinct and has various skills and abilities that allow one to mix and match and encourages trying out different classes for skills to bring in to another class that would benefit from it.
I'm not saying AQWorlds SHOULD be like DD but there are many things it could learn from it not just in DD but in many other games in general that would greatly increase how enjoyable AQW is.
In terms of farming I don't dislike farming, in fact many of my friends think of me as a hardcore farmer/grinder when it comes to it. Personally when I farm I do it for two reasons one would be it looks nice the other it will help me become stronger in game (but if the things is useful but ugly as in don't expect me to touch it unless I can hide the ugly). However farming for Rep is so painful it makes me want to go in a corner and cry most of the time. I'm almost done with Arcanegrove for (E.) Shaman and let me tell you nothing takes away the fun than the climb from Rank 7 -10 as that is where the midway point is.
However the fact that you're about 2 - 3 Ranks away from complete gives one the illusion they're nearing completion only to be met a single Rank up after 3 or more hours of nothing. This is most prominent in those last few Ranks because Ranks 1 - 6 have the nice little "Congrats you're now at Rank X of A" which gives a sense of progression. It also makes little sense in the game as I'm pretty sure I don't need to do small time jobs just to gain their trust after saving them from "insert Chaos Lord here".
Make it so that after the main storyline quests It get left at around Rank 7 or 8, or have a different method of farming rep all together like adding a mini-war system that awards rep instead of progress? Or everyday there is a specific type of monster the region wants killed and each time you kill it you gain a rep alongside your CP, EXP and Gold? Just a thought. Other wise Merge shops and other long quests are pretty fine in my book as it gives you the feeling of for every item you have you get closer and closer to your goal, it's mostly Rep where I have beef with.
Another thing I like to see focused on is the story. I know it means little in actual gameplay but it really gives a vibe when you're doing something because you feel a connection to a NPC or the end result of all of this is something you really want to happen instead of because the game told you to. The reason I considered playing AQW again was because of a slight detour going to the Dragonfable TvTroupes page and man was there stuff that my 11 old self really glossed over (What do you mean Robina being Victoria was obvious?!).
This also can go and relate back to quests as quests is equivalent to the story progression through the game. For example I felt everything with Escherion to be very nice, you get to see the Lord's power through the appearance of the map and everything felt nicely paced with some nice AE brand humor at the end (though I did think the ruins was kinda boring). Vath however felt like a slog, too many events and quests I felt like were just there to pad everything out and not enough of Vath himself to make me care. Did we really need so many quests to get into Dwarfhold? Do we really need the key to break just for more quests?. While Discordia had far too little quests to make me care about what's going on, each one felt way too disconnected and Kimberly was introduce so far in the end otherwise the twist would've really have got me.
Though this has little to do with the Server Rewrite in general the overall content of the quest is also something to take note of. I get it Kitsune is stirring up the Yokai, go and subdue them but then suddenly we go to the Yokai River and it's suddenly "I'm hungry make me sushi?" Like what? Good examples of the story/quests done right were Escherion, Ledgermayne, The Chaos Twins all of the Throne of Darkness (at least most anyway) and Sleuthhound Inn (personal fav). Though I haven't done all of the 13 Lords of Chaos quests to comment on anything else, on top of what I have said previously I would like more of the NPC's to get more spotlight most of the time I feel like it's Artix, Gravelyn, Dage and Nulgath taking front and center really with the two former having any meaningful character development. Otherwise if it's anyone else it feels like someone else could've taken the roll and still achieve similar effect.
I would like to personally request the ability to "overlay" weapon appearances over others. For example if I want the benefits of the BLoD but would like Avatar of Death Scythe as my weapon cause looks I can make it so that I get the ability to turn undead into butter but also have my cool glowy scythe with me. I think DF had this ability I "think" not sure been too long...but it would be nice just so that I don't need to sacrifice performance of fashion...except inventory space but it is a small price to pay for the sake of looking cool.
Anything else I would like to say about Classes and Enhancements has been said before but better and due to my limited knowledge on the subject (I haven't dabbled in Luck...gonna try that out) I think it is best for me to pass on this one.