I've posted a more accurate version of the map.
In the section you mentioned, there are a secret door and a secret (trapped) brick. I still ignore the function of the brick: since it is not necessary to access the second level and since it seems it opens no door, maybe it is just a trap. Tell me if this is what you were looking for.

Yes, I believe you can go through that dungeon without using Levitation Spell.
However, Levitation Spell is almost mandatory in the Kingdom of Eternal Sin, so I would learn it in time, if I was you.

Conserning Eternal Sin quite the opposite - I completed it rather easy without Levitation, but I simply couldn't finish Pandemonium without it. Maybe I didn't do everything that was planned by the game but teleports just didn't send me to where they were supposed to.

With Ecclesiastical Tomb I meant the very east part (not to go down to lovel 2) with two walls each has a brick (place that you described as "secret trapped switch (brick)" on your map). I need to get to the right one.

There are a lot of damaging pits there, I can't figure out how you were able to pass through easily. Maybe, it depends on elemental resistance or something like that - I almost died anytime I passed a pit without Levitation spell. In which level are you stuck exactly? Maybe "1e"? I've found a lot of levers there, and I suppose their function is to activate some of the teleport. But I had no problem with teleports, so I did not examined further on that matter. Did you pull all the levers I've spotted on my map? Anyway, I can't exclude there are more levers there that I did not discover/highlight. In that spot, I've found just one brick and I've Perception skill on maximum level: I don't think I've missed something...

I pulled all levers. I can't tell where exactly I stuck. I already finished Pandemonium but only thanks to Levitation. Firstly I stuck on E and F then I learned Levitation and completed it right away, so I don't know about G. I can only say that it seems I had problems with levels that have levers.

And it seems your maps are all right - before learning Levitation I checked levels E and F very carefully. Did you yourself use only levers and it worked?

Concerning Ecclesiastical Tomb - as you can see: two walls, each has brick. To the left opens left wall - to the right does nothing. So the right room has iron gate to the left and wall to the south. And I can see the right room itself. This very room I can't reach.

Finally I understand!
I did not discover that area before.
Unfortunately, I found no way to open that door, I've already tried.
Only, I noticed that a lever in the first secret area, apparently, does nothing.
Also in the second level, a lever is apparently useless. Both are in a group of three. I indicated them generically as "lever" in my maps.

"Only, I noticed that a lever in the first secret area, apparently, does nothing." - where is that?
You finished Pandemonium without Levi.?

And can you please check one thing for me - push that highlighted brick I pointed - it is level 3 SEC. tomb - and then tell me if the game throws you back to Windows, will you? Because I'm thrown.

link
The ones identified as "lever". Nope. I used Levitation, but I realized that with all teleports active, I could go through it without Levitation. The question is that it seems that if you don't pull all the levers, some teleports remain inactive. I will try this ASAP.

Have you encountered NPCs missing and barrels that when you click on them your hero walks to them and stands right where they are and doesn't destroy them?

Yes.

I could not find this area in level 3.
If it is level 2, I had already passed through that secret door without problems.

Yes, it's level 2, I'm mistaken. You probably clicked on the wall itself... But you don't click on the wall itself - when you click on the wall it moves but it moves not because of that brick. Make the wall closed and click on that brick whle the wall is closed. Also try when opened.
So you have both missing NPCs and bugged barrels?
And did you have barrels that when you click on them your hero starts destroying it but never can. I myself did about 2000 damage and still nothing?

I came back there through an old savegame and yes, clicking on the brick the game crashes... LOL. During a quest, a NPC disappeared.
3-4 times, I've found a barrel that when I clicked on it, the character got closer and did nothing. In the Coliseum Dungeon I've found a barrel that I was able to open only thanks to Shatter spell - that destroyed it.

Do you know what is it? Can we get there?

And if you be able to get in east room in Secular Tomb - write down how.

No, I cannot enter there because, despite what the map shows, in-game that building has no door. Originally, I clicked on the door, instead of the brick, and got inside the secret area.