Currently in the Lucy Opendev, there are 40 EQs from 40 cultures. Here, I try to categorize how each EQ get their bonuses, in order to lay out their effects in a systematic way, and to figure out why some of them are too powerful and some others are too weak.

From Ancient Era to Early Modern, we have:

    5 EQs that are stand-alone (they don't receive bonus from anything around them): Harappan Canal Network; Goth Tumulus; Roman Triumphal Arch; Aztec Sacrificial Altar; Umayyad Grand Mosque.

    4 EQs that receive bonuses from generic adjacency (every adjacent district can give them bonuses): Greek Amphitheatron; Ghanaian Luxuries Market; Teuton Kaiserdom; Ottoman Sultan Camii.

    4 EQ that receive bonuses from adjacent terrain feature: Olmec Heads; Zhou Confucian School; Khmer Baray; Edo Japan Tera.

    4 EQs that are Forts/Garrisons: Assyrian Dunnu; Mycenaean Cyclopean Fortress; English Stronghold; Polish Barbican.

    3 EQs that replace Outposts: Hittites Awari; Huns Ordu; Mongolian Orda.

    3 EQs that replace Harbors: Phoenician Haven Port; Carthaginian Cothon; Norsemen Naust.

    3 EQs that receive bonuses from adjacent Religious District: Frank Scriptorium; Mughal Jama Masjid; Spanish Catedral Gótica.

    3 EQs that receive bonuses from adjacent Makers Quarter: Nubian Meroe Pyramid; Egyptian Pyramid; Mayan K'uh Nah.

    3 EQs that receive bonuses from adjacent Farmers Quarter: Babylonian Astronomy House; Aksumite Great Obelisk; Haudenosaunee Three Sisters Plantation.

    2 EQs that receive bonuses from adjacent Market Quarter: Achaemenidian Satrap's Palace; Venetian Botteghe di Artisti.

    2 EQs that receive bonuses from exploitation (they shouldn't have any other quarters next to them): Mauryan Stūpa; Joseon Seowon.

    1 EQ that receive bonus from adjacent Commons Quarter: Ming Grand Teahouse.

    1 EQ that receive bonus from adjacent Harbor: Dutch VOC Warehouse.

    1 EQ that receive bonus from adjacent resources: Byzantine Hippódromos.

    1 EQ that exploits tiles around it (it works like Hamlets): Celt Nemeton.

However, there are also some EQs that have a much stronger stand-alone bonus than their adjacencies. These are: 

    Egyptian Pyramid (+2 industry and exploits industries around it)

    Mayan K'uh Nah (+5 industry and exploits industries around it)

    Dutch VOC Warehouse (+5 money per trade route passing though the territory)

    Byzantine Hippódromos (+5 money per horse the player owns)

    Mughal Jama Masjid (+2 industry to every worker and exploits industries around it)

From above examinations, there are some balance problems that are quite obvious:

    1. The "true" stand-alone EQs are far too weak. They provide very trivial yields and will even destroy the original yields on the terrain. 

    2. The "having adjacency but stronger when stand-alone" EQs are far too powerful, especially when their stand-alone effects can stack infinitely under the current quarter-spamming mechanism. For instance, spamming Hippodromes and VOCWs will stack that +5 money on top of each other, resulted in massive gold income.

    3. Another problem of the "stronger stand-alone" EQs is that some of them (Pyramid, K'uh Nah, Jama Masjid) can work like a Makers Quarter - they will exploit surrounding industries - and Makers Quarters are already too powerful since there are too much terrains giving industry. They are basically super-charged Makers Quarters that provide even more industries.

    4. This also brings the problem of the Market Quarters, that is, they are too weak - there are literally no terrain that can yield money and Market Quarters cannot really exploit terrain yields. As a result, EQs that are depending on Market Quarter adjacencies, Satrap's Palace and Botteghe di Artisti, become very weak as well. The industries invested in building Market Quarters are not worth the return.

    5. "Generic adjacency" EQs can be too powerful as well, since they can receive adjacency bonus from themselves, and currently quarters are spammable. One can make a carpet of Kaiserdoms which yield tons of industry.

    6. Among EQs that receive bonuses from terrain features, Khmer Baray is too powerful, it really extract a lot of things from river, and finding a Baray placement next to 3+ river tiles is not that hard.

    7. Some trivial balance points: The Forts/Garrison EQs can be very situational. The Common Quarter based EQ, Ming Grand Teahouse, requires a lot of investment to reach a considerable output, unless one spams Commons Quarters around it.

Therefore, several possible suggestions can be made:

    1.Giving stand-alone EQs an adequate stand-alone yield, or adding some adjacency yields. For example, Roman Triumphal Arch would better have a generic adjacency, as historically they were built in the city center, surrounded by other districts. The same goes for Aztec Sacrificial Alter, they were built in the city center as well.

    2.Making quarters not spammable, such as adding a scaling upkeep on repeated quarters, or outright set up an Era-based cap. Quarter spam is one of the major balancing problems in the current version of the game.

    3.Making Makers Quarters less powerful. There are already a lot of talks about the Makers Quarters' OP-ness on the forum. My two cents here is having less terrain types that yield industry, in addition to mechanics that can limit quarter spams.

    4.Making Market Quarters more powerful. For example, adding terrain-based adjacency bonuses for them, such as every adjacent luxury give +3 money (instead of the current poor +1), or every adjacent river tile give +1 money.

    5 and 6. simply dial down their bonuses would be a good start. Why would Kaiserdoms having an output larger than Coking Works (Industrial Era EQ)?

    7. Some small tweaks here and there will be fine. Personally I would suggest Teahouses having a generic adjacency bonus, as well as a Zone of Control around all the Fort EQs.

Overall, more balancing works are needed in the of quarter mechanisms, especially the Makers Quarter problem and the quarter spamming problem; an unbalanced OP mechanic is fun in the short term but will reduce the complexity and replayability of the game in the long run. In any case, looking forward to the full release.

I think you overlooked one very important dimension, which EQs can be placed anywhere, like hamlets, and which have to be put adjacent to existing district, luxury, wonder etc. This is one of the reasons why Egyptian EQ is super strong early on, though after some analyzing, if you play your cards right, you can get close to similar effects by correctly placing stone rings, taking advantage of luxury resources placements etc. along side a single nice maker's quarter.

I agree with the currently huge imbalance between the market and maker's quarter. Now money itself is still super viable strategy, but that is because of other EQs and ones not related to market squares.

Either way, being able to make a few impactful placements early game is super satisfying, but they could easily take some more time to build (increased cost), while late game carpeting stuff with districts is not so fun anymore. Now this could be improved perhaps with UI changes.

 * Also, if one doesn't know that they can hold shift to queue the same thing multiple times, then that sucks

 * You cannot queue districts if they require an adjacent district even though you are already building it.

    * This could be solved easily, if you delete a district, that is required for another district in the queue, delete that from the queue as well

    * If you try to move the second district before the requisite district, then it just pushes it back.

 * showing the resource gains for placement taking into account what if everything in your queue is already built)

Even then, it is still unimmersive.

In general it looks like a solid mapping of the EQ-s powerlevel, but when balancing it one should also consider the Legacy Trait, cos it is fine if a civ has a solid legacy trait but a meh EQ. But some of the most useless ones could use some love.