This is solely a thread based on opinions from the perspective of a player who's been around since beta, and has played a few other MMOs. Below I will be detailing my thoughts on the current state of ESO and what I think can be done.
PVE: I would like to consider this game as probably the most fun PVE experience I have in the casual terms. Nothing takes crazy long to complete (regarding solo content such as quests, delves, public dungeons, ETC.) While I am not mainly a PVE player anymore, it is where I go when I just want to play ESO and have fun. I do not get into the competitive score-running end of PVE to say much in that regard. I think Overland content could definitely get scaled in difficulty (Harder quests, delves, public dungeons!) as if it wasn't easy enough, we have companions now!
PVP: God... PVP needs some major love. In the past few years of my ESO career I've gotten immensely into the PVP aspect of the game. I've played (To a basic extent) every class and spec. (Mag/Stam) The balance is horrendous and only seems to degrade further in my opinion. The balance would be remotely forgivable if PVP didn't run like hot garbage. (Looking at you, Gray Host!). Desync, crashes, freezing, lag, skills not firing. The content is immensely stale. Getting a few new siege engines or an occasional bit and bob isn't really interesting.
Guilds, Trade/Economy: Honestly, as a GM I love what ESO has brought to me in the terms of community. I have made many memories, made good friends and got to grow as a person and leader! But my only qualms about guilds are...
1. There needs to be something more to do with them! Like an official guild hall (Such as a purchasable castle, for instance) that you can upgrade with NPCs like merchants, guild merchant/banker. While having player homes function as Guild Halls where one player can accumulate all mundus stones, crafting stations, target dummies, and more is absolutely phenomenal, but it would be good to have an "Official" way to expand upon that system!
2. Guild Vendors: I have no qualms with the trader system as it is.. But I would like to see it functionally expanded! I'd love to build my own guild store building, or have NPC's actually stocking a store or doing something beyond shouting out that they're selling goods! I'd love to see traveling traders, supply lines, ETC! Bring some life into the world!
3. Guild Keeps/PVP Claims.... Seriously, this feature almost feels like kind of a joke. You get to display your banner on a PVP keep/outpost, and it changes the guards to wear your tabard, and displays your guild store... But thats it. There's no PVP boon to holding a keep for a guild, no way for you to strength the claim or really give cause to care unless you're treating it as an honor claim. "They took our keep!". I would personally love to see PVP guild keep claims... mean something!
4. Guild Summary: Well, in a short clarification of what I was speaking about. The Guild system is an immense goldsink as it is, but it could be made even better with more functionality and aesthetic!
Combat in ESO:
1. PVE: In PVE, once you get a basic standpoint of how combat works, and you can at least hit 20k DPS, you can do a majority of content in the game; including all normal mode dungeons and trials with relative ease and tanking or healing these things is not challenging (IN MY OPINION.)
2. PVE Veteran Content: Depending on just where you're talking about.. Base Game veteran dungeons are not too bad at all, DLCs become more mechanic and dps-cap dependent in some cases. I think this is pretty healthy, as any 4 man content can 100% be taught and learned through a group if the effort is put in. Arenas are a pain on your first solo runs. (VMA, Vateshran.) I have not extremely dipped into Vet Trials myself. (By the time I really got into trials, I swapped to favor PVP much more.)
PVP: The combat is fast paced and can intimately result in who places the well timed combo, who keeps buffs and heals up, and who has the sense to keep up with what's going on! This is great, PVP combat never feels "Stale"!
Just some thoughts I had mulling about. I wish the best for ESO, and I'd like to see new features involved in ESO that don't have to do with just our skills/character! Having expanded guild, economy, and PVP features/content would definitely give this game a major boost in my mind right now!