What I have learned so far replaying Japan a few times.

I may still be wrong but here are my observations:

1- The often scapegoated Landowners are NOT evil. Nor are the laws that are often there at start. Landowners derive wealth from farmland taxes and are only second to capitalists in contributing to private construction. They are also the second biggest consumer of goods and are the prime source of graduation to other professions when you start off as a low SOL, low qualification nation.

Yes, you CAN keep the Landowners permanently through the whole game. In fact they contribute more to SOL and private construction than farmers on a pop by pop basis, which is why the most progressive agriculture law, Commercialized Agriculture, still gets you to keep Landowners alongside Aristocrats while freeing peasants from serfdom.

2 - Clergy are NOT evil either. They are what's keeping a low SOL yet high literacy Japan from assploding with radicalism that threatens your nation with populist feel good laws prematurely that tank your economy - like instant Homesteading while most of your farms are still subsistence or Consumption Taxation while your nation has very few consumer goods factories. A powerful and satisfied Clergy provides huge authority bonuses, but more importantly a massive decrease in radicalism from low SOL, greatly stalling radicalism from rising for you to hopefully raise your nation's SOL in time....

which reminds me....

3 - Laws do NOT prevent radicalism (though they help). Killing off 'evil' IGs do not prevent radicalism either. The elephant in the room is actual development of your nation. A noob may try to exploit and oust the Shogun immediately with day 1 Homesteading, only to find Japan DROPPING in taxable income while having a meager increase in SOL (peasants being freed from being slaves) before the SOL drops back down (farmers taking over from landowners via Homesteading are actually poorer).

The truer, best way to raise SOL is in genuinely developing your nation, which brings me to another issue.....

4 - Laborers are even poorer than peasants - so spamming factories or removing subsistence farms actually tanks your SOL even when you succeed in raising your nation's GDP. Again, laws do very little to alleviate this situation. They only work to -enhance - the effectiveness of existing genuine measures that manage to raise SOL, not to be the cause of it.

5 - The only genuine way to raise SOL I have found so far is to build consumer goods, AND research production methods to optimize production of those goods. If I do only the former I tank the SOL. This is because you need to counteract the proliferation of extremely poor laborers with the increased productivity of goods production per pop.

6 - You need to actually keep the 'evil' rich guys such as Capitalists and Aristocrats around to be the prime consumers of consumption goods. Killing them off with exploited revolts will just tank your GDP - plus revolts destroy certain buildings in the process and devolve the technologies of buildings which require significant time to evolve back up. Also as mentioned already previously, they are the easiest source of qualifications. The presence of existing middle and upper classes is always better than praying that upper class jobs get generated through literacy and spamming universities.

7 - always, always go for the production methods that eliminate the use of laborers as much as you can. Follow up each wave of unemployment from laborer employment elimination by immediately building new jobs for them. Your GDP may tank a bit every time you introduce a laborer-reducing production method for a particular industry, but in the long run your GDP and SOL will rise.

8 - You don't NEED to pass certain laws to get the IG guys you want to pass the laws you need. I experimented with raising Japan's literacy, GDP and SOL while still being an autocracy and a seemingly 'invisible' Workers IG enacted a movement to get Homesteading with Critical level. I don't even need for Universal Suffrage to get Workers visible to make it happen. Likewise, Total Separation pushes happened after my Japan with State Religion had significantly increased literacy level for Intelligentsia IG to become stronger.

9. laws like Universal Suffrage are meant to enhance, not cause, certain IG groups to become powerful. Actual economy does. You can be a technocracy and Rural Folks WILL dominate the IGs if you have very little consumer goods factories yet a ton of farms.

10. Maybe it's better to actually set aside certain glass buildings to just build glass and not also build porcelain. Because steel construction requires a fuck ton of glass, and an attempt to actually mass produce glass will often be met with a refusal by glass factory owners to produce glass because the luxury byproduct, porcelain, gets way too overproduced they become too cheap and unprofitable.

11. Yes, construction maxxing is meta, but must be coupled with tax capacity maxing, consumption maxing and laborer busting. Otherwise you would just raise your GDP while ranking your SOL while keeling over from prematurely passed progressive laws. Also the later laws are so expensive to research you need to set aside significant attention to build like 30 - 50 universities.

I may be wrong, but at least these are my impressions for now.