The Belgian Revolution in 1830 was not a fatality. Belgians were not overaly enthusiastic at forming a United Kingdom with The Netherlands in 1814, but its elite went into it with the idea of trying to make it work.
The United Kingdom could have lasted under some conditions: more liberal policies by King William I (i.e. accept ministerial responsibility), not interfering with the Catholic church - esp. in the area of education, having a more balanced policy for nomnations in the high ranks of the administration (which OTL were outrageously in favor of the Dutch). His economic policies were otherwise much appreaciatd by the nascent Belgian capitalist elite, and he had a lot of support in cities like Antwerp, Ghent, Liège, Verviers, etc. Even after the September days in Brussels, he could have kept the Kingdom together if he had accpeted administrative separation and putting his son in charge of the Southern provinces. Instead he ordered the bombing of Antwerp, and then differences became irreconcilable.
It is possible that incidents could occur in the Southern part of the country in 1848, but I doubt a national revolt.
It is also true that the center of gravity of the Kingdom would have inevitably moved towards Belgium, for demographic and economic reasons.
Regarding the status of Flemings, it is clear that Flemish-speakers only progressively got equal status as French. Formal equality between the two languages was achieved in 1905 IIRC. Am surprised about the story of Civil Code being translated only in the 1960's. In any case, even if this were true, justice had been in Flemish in Flanders long before. Local civil justice (called justice de paix in French) could be rendered in Flemish all the time. It is for intermediate and higher vourts and for penal law the things were more gradual. Same for education. Flemish-speakers were objectively discriminated for most of the 19th century and early 20th century, though the practical consequences of this discrimination are, in my view, much exaggerated by a certain streak of Flemish nationalists.
One thing to realize is that th language distinction was more of a social distinction than one between North and South. The nobility and higher bourgeoisie spoke French in both parts of the country. In the South, the popular language ws still mostly Walloon at the time of independence. Migration towards French was easier in Wallonia, due to linguistic proximity, non-existing literary standards (which somehow existed for Dutch/Flemish), and lack of historical conscience (the corresponding territories having never constituted a hoùogeneous political entity as the county of Flanders could seem to be).
would be for the revolution to be repressed with more power.