You can easily strafe in non-mouselook mode by quickly holding the right mouse button and hitting 'A' or 'D'.
Granted that it requires some observation and/or prior knowledge, but Quells don't move much. The room provides a huge column that you can hide behind. They can dispel, but they'll have a LOT more trouble dispel'ing a high level cleric hireling's Deathward than your Flesh Render visors.
Also, beyond that quell are 6 orange named Vampire priests, 4 red named Vampire honour guards, and numerous yellow named Vampire trash mobs. They're all dangerous with their stat drain, and the priests MAY be able to enervate as well. All the vampires are able to dominate you, so you need to have some source of Protection from Evil (long lasting clickie, Fragment of the Silver Flame [from Church and the Cult], the aforementioned Silver Flame Talisman)
A monk is one of the strongest solo'ing classes, but one of the DnD principles is that every class has a weakness. For a monk, that would be level drain. It's still not as dangerous as other classes weaknesses because monks are far more mobile than most other classes. You are better able to dodge or avoid a mob's attacks, and therefore can use the terrain more to your advantage.
DnD design (aside from solo quests) tends to balance things for a party of 4-6 people, and DDO tends to do the same. This Quell IS balanced for a group of 4-6 at-level players. As mentioned, dungeon scaling will lower the mobs attack power and HP, making it easier to handle for a group of 1 or 2 as opposed to 4-6, but some abilities that are a problem for 4-6 can be overwhelming for 1-2. Level drain is one of these, and there is not much that can be done to balance it for a 1-2 member group. In order to manage it, you need to think of alternative strategies to mitigate its damage.
Solo'ing at high levels is definitely possible, but it REQUIRES foreknowledge of the quest, experience handling the mobs, and the equipment to make up for the lack of other party members. You're off to a good start, but you don't yet have the experience with the mobs and quests yet.
The Necro series' in general are not solo friendly. There isn't much that can be done in that area without prior knowledge of the quests. If you truly want to continue solo'ing, the Lordsmarch quests, the Gianthold side quests, parts of the Vale, and parts of the Inspired Quarter and the Dreaming Dark are good for it. Necro, Amrath, the Gianthold main quests, and the rest of the Vale can be solo'able but are not anywhere near as easy to do when you don't have prior knowledge of the quests and mobs behaviors.