I have seen a few general issues raised that I would like to address:
1-There Aren't Many Mid Level Dungeons Available: I would have to disagree. There are quite a few mid-level dungeons available outside of Har'Akir, and a few within Har'akir that do not have traps, and a fair number of them don't even require you to be able to open locks or disable traps. I will include a list of ones I can think of off the top of my head below in spoiler tags.
The Neureni Cave, Darkling Camp, Swamp Men Camp, Lysaga Hill, Shadow Cave, Port Sewers (Assassin Bugs), Cave in Ghakis (The first one after you take a left before the transition to the transit before Krofburg, what it spawns is randomized like the Sullen Woods but a fair number of the spawns are suitable for mid level), Ice Palace, Alhoon's (There are trapped chests, but dungeon is perfectly doable without a rogue, and the traps can be bypassed with the old method if you are able to avoid their damage, or if your character is masochistic enough to take it for the loot), Lich Cave (Again, there are trapped chests and some traps on the ground, but they are avoidable and not really lethal, negative traps are more focused towards debuffs than dealing damage), Cave system in the area before the Crossroads and the house with the devils it connects into, Catacombs under VoB church, the DOOM well in VoB, Rat Cave in VoB. Those are the ones I can think off of the top of my head. In addition, mists themselves can be considered a mid-level area.
2-Rogues Are Useless OL/DT Slaves: Again, I will have to disagree. Keep in mind that we are not talking about just pure rogues, but multiclass rogues as well. I myself have been playing a multiclass rogue for some time that I would consider fairly combat effective, and I have seen numerous multiclass rogues who were more than able to pull their weight in a combat situation, mundane and otherwise. Pure rogues are not great on the server due to the AC numbers of higher level enemies and abundant sneak attack immunity, but you can still make a rogue that will be able to pull their weight until end game content and multiclassing is made easier and simpler by the server, due to changes such as the multiclass exp penalty being removed, as well as there being some great options for a rogue to multiclass into without sacrificing much if anything from their RP.
3-Picking Locks/Disabling Traps Is Not Very Engaging For The Party: There is a certain bit of truth to that, as the outcome is quite binary, the visual aspect is pretty much non-existent and the result itself is quite binary as well. Ideally, more of the traps would be party wide affairs that are half puzzles, but engine and time restrictions make that unlikely and unpractical. However, I would argue that this also has to do with the RP around the whole affair, and I will point to bards or other characters singing or performing as an example. Due to the medium, you can't hear the music, you can't see the performance whether it is a dance or fingers moving on a fretboard. And if you have someone just making a [perform] roll, then it is indeed quite boring. But on the other hand, you have those who prepare lyrics for the songs, engage the audience in some way such as chatting with them and leading into the songs, describing the actions or songs in a way that is simple but understandable, then those things make the performance much more enjoyable and engaging for everyone involved. I think this would work in the given context as well. I myself tried to do this at times if I knew the party I was with wouldn't mind holding up the murder train a minute longer for some RP, making up descriptions for the traps and what my character thinks of them, or asking for help in simple matters such as "can you put your finger here?" or "can you get me this tool or that" in hopes of making it more engaging for everyone. I think trying to add a bit more RP flair to it, alongside of a change in perspective by the players that these changes hopefully will facilitate, will help this problem. Making the traps more threatening as Philos suggested would also be helpful, perhaps even making it so some loot is inaccessible if you trigger a trap, the vault locks down because security is engaged. Though that would be quite a sizeable undertaking, and I am not sure how practical it would be.
4-It Is Dumb To Have To Have A Rogue: I don't think that it is senseless that you would require a certain composition or balance of classes for adventuring, and I would argue that it is intended. And while PnP DnD often has multiple classes that can complete the same task, they are also working with an average party size of 3-6, not dozens like a NWN server, and even in PnP rogue is a staple in most parties. Furthermore, I don't think it is silly to need a rogue to go grave robbing in a place that you know is full of trapped temples and tombs, intended to lock away the treasures of the long dead and keep them safe from people like you. I think it fits the narrative of the region and dungeons perfectly, as well as the Ancient Egyptian flair it draws on. In addition, thanks to how flexible multiclassing is on this server, you can have many different kinds of rogues that fit different kinds of situations, whether it is on the front line, ranged support, or some sort of magical support. Overall, I don't think the new changes make them a must, except for a sizeable chunk of Har'Akir, and they are definitely not any more necessary to have around than some sort of caster capable of buffing for dungeoning. In the end, even though it might be inconvenient to need a certain class for some of the most convenient dungeoning spots for mid-level, I don't think it kills mid level dungeoning in any way but adds to the flavour of a region.
5-Now You Simply Must Have A Rogue To Be Able To Dungeon: As I pointed out above, there are many dungeons in the mid level range that do not require a rogue at all, so I disagree with the idea that "you can't work around not having a rogue for most dungeons." Even for higher end dungeons, I can think of several that do not require any trap disabling for anything other then loot, and some that don't require it at all. And the traps on chests can still be handled the old fashioned way, not to mention I think it is perfectly fair to need a professional if you want the really good loot. Perhaps the loot containers in these places can be adjusted to have some of the loot in containers that are not trapped or loocked to make it more fair. Overall, however, there are still plenty of dungeons you can enjoy, and benefit from, without absolutely having to have a rogue.