First you should Know that dim should be the first curse in your stack...It won't overide the others. The AI curses except terror will override the other curses and dim loses to all of them. Other than Atteact the damage curses will over ride the AI ones. When useing dim with other curses you have 2 choices keep it small and use as a spot fix for small areas of ranged attackers, not a bad idea at the begining but the duration is bad in NM and worse in hell. Or you can pump it up and make it huge (i like 10 points by the end of norm, 5 more through nm, then max it in the first few levels of hell.) This way you can Dim well off screen and take your time setting up the mob.t back a little to give it time to set.
Aways remember with Dim beasts that are moveing when dimmed will continue to finish the action they were doing. So when you dim retrea
I know you've read my mojomancer guide and there are a number of powerful mixes if you plan your curses appoerately.
Champions and those rated stronger are immune to the curses somewhat though not completely. If you know how the curses work they are very powerful, especially when stacked with other curses. Some examples:
Just becasue they wont get confused/ attract doesn't mean you can't use this against them. They will attack those that are confused or attracted, likewise the confused will attack them too. So simply cast IM or LT on them and confuse the crowd around them, they will attack back and either kill of the crowd around them with IM or with LT the crowd will kill them since the lesser bests will take advantage of the LT.
Also when a confused monster casts spells like firewall, meteor, inferno etc. It will hurt everything that enters that area, includeing its self in the case of beaasts that cast firewall and metoer.
If you are very careful about keeping your radiuses in check you can easily use a variety of curses to completely controll the situation. For example if you use alot of CE a good tactic is to make sure your Amp and CE are of the same radius, confuse of a radius at least twice (ie 12) the size of attract(ie 6). With your curses you can for example cast confuse on the crowd, then pick one in the middle of the crowd to attract. This will casue the middle of the crowd to concentrate on the attracted, since the confused are also attacking those drawn to the atttracted the group of monsters will actually get smaller. Then once the attracted is dead cast your amp on its corpse and then CE, Should kill off most the group since even though they don't hit real hard for how many HP they have, they have slowly whittled themselves down considerably. You could also cast say a spell like IM on those that are attracted since they will be tied up in the middle anyway, further weaking the surrounding crowd. Decrept works well in the middle too, especially on the bigger monsters.
Also spells like PE are great for this too, a fairly small amount of points are needed in poison explosion are needed to make it deadly, and to colapse a crowd down like desribed makes it very deadly.
Terror has the added benifit of temporarily overriding a curse, you can use this to herd the monsters where ya want them, or for example send more mosters to one that you attracted. Once terror has wore off the curse it had previously will remain so you can send the confused and dimmed to places that you'd rather have them. This is a great way for a mojomancer to run without summons, keeping the last standing monster in a group dimmed and simply terror them ahead to where you are heading. Then cast confuse or attract on them to start the next group. This works better in open areas than enclosed areas, cause terror wears off when a beast runs into an obsticle. Since this beast is usually weakened significantly, it makes a good fast corpse for CE on the next group too.
Also remember that when useing confuse a smaller number af allies on the screen are better, it reduces the number of targets the beasts have to choice from. I'd typically only recomed a golem and merc. at the most. Once you get the hang of it you really don't even need them other than for bosses.
Part of the myth of these curses is that they don't work well, and I assume much of the myth is from the fact that the most common necro build is the summoner, and with many targets to choose from the confused will attack a significant number of skelles, making the average player feel these spells dont work.
Also if you stack your curses a lot you need to keep track af radiuses and how they compair to your other spells. For example I talk of using CE. If you let amp get bigger than CE then you will most likely overwrite the AI curse of beasts that wont get damaged by CE. However there would be no harm in letting the CE get bigger than the amp. So you really need to keep all plus gear in check. It's often best to look for items that boost specific curses if your style requires a balance like this. Better items will be +dim, confuse, attract. Stay away from terror, it's usuallly best small. also gear that adds to your other lines are good too, a good clay golem is recomended, treat him well and he'll keep you very safe.
Also I should say bone walls make great barriers for cursers, slowing down would be opponents and giving them more time to consider targets other than yourself.