>Alewites

I think its important for you to clarify if you're asking about the Alevi, who are mainly Turkmen in Anatolia or the Alawi, who are the Arabic people living mainly in Hatay today and in Syria. These two groups are different and share not much in common except both revere Ali and their name.

Unlike their sister sect, the Bektashi, who at times had good relations with the Ottomans, the Alevi had a very violent relationship with the Ottomans, heck, the lands that the Alevis historically and traditionally reside today used to belong to proto-Alevi beyliks such as the Beylik of Erzincan, Eretna and the Danishmends if you want to go further back. Erzincan for example fought against the Ottomans under Timur.

Going forward in the timeline a bit, the Alevi were transformed from heretics (as a fifth coloumn) to heretics who support the Ottoman rival; the Safavids.

Safavids, before they were a state, were a military-religious order who spread their word in eastern Anatolia (where the Alevi reside today) and their adherents were the Qizilbash. It is important to note that all Alevi are Qizilbash, as in those who follow/revere Sheikh Haydar and Sah Ismail and thus enemies/supporters of enemies as far as the Ottoman state was concerned.

With the ascension of Selim the Grim (who is cursed by the Alevi along with Yezit) Ottomans would increase the horrific persecution of the Qizilbash (following the footsteps of his father who issued the first fatwa against them) and would go on to put many of them to sword (40000 as far as the Alevis are concerned, but some argue that the total number was much much smaller) as well as instigating wars against the Safavids. Selim despised the Safavids.

A pivotal moment in the Alevi/Qizilbash history of Anatolia is the Battle of Chaldiran where, with the Safavid loss, eastern Anatolia was secure under the Ottomans and the Alevi seemed destined to persecution. Many Alevis fled to Iran.

Alevis would always be a fifth coloumn in the Ottomans, until the fall of Ottomans, and they can be found in many major revolts such as the Jelali revolts.

After the fall of Ottomans, I cant really comment as to what would have happened to the Alevi since quite a bit of the land they live in would be shared by the Allies.

Ataturk, however is seen as a saviour by Alevis who tore down religious order and brought about secular living. However he also had roles in the Kocgiri and Dersim rebellions whose outcomes were...unsavory to say the least. He remains an enigmatic figure for many Alevis who at least revere him as the father of Turkey as well as bringer of secularism.

Those who might be interested in the social landscape of Alevis and how they felt/spoke about their lives in medieval anatolia might want to check out the poetry of Kaygusuz Abdal and more importantly Pir Sultan Abdal and others of the "7 ulu Ozan".

I apologize for this answer which seems all over the place

Some of the sources I've used for this answer are;

Rıza Yıldırım's "Turkomans between two empires: the origins of the Qizilbāsh identity in Anatolia"

Uyur idik Uyardilar by Irene Melikoff

as well as Alevi religious leaders, the Dedes, and well, I'm Alevi.

Edit; Since you were also asking about Kurds and other minority, I might as well as say that I am a Zaza Alevi (though I dont think the Zaza are Kurdish, but many do) and that 1/5 of the Alevi are kurdish and funnily enough 1/2 of Zaza are Alevi the rest Shafi

I am not informed to say much about the post WW1 divisions between the majority Sunni and Shias of Annatolia known as the Alevis, but i can say that Western imperialism was not very signifigcant in it. A history of conflict exists between the Sunni and Shia going back to the 15th century in particular (although the conflict goes back before then) with the wars against the Shia Persian Safavids including multiple brutal massacres against the Shia. Western rivalry especially that of the Russians was more important in the persecution of Armenians as they were seen as dangourous fourth collumn on the border of an expansionit russia. If we are talking about the situation in the Western protectorates of the Middle East after WW1 the various colonial administrations favoured certain groups at expense of others (The British favoured the Sunni in Iraq and the French supported the Allawites in Syria) but this would be after the Ottoman rule in these lands and these divisions firmly existed beforehand. The Ottomans until the end of their empire administered people according to religious divisions and Westernisation as taken up by Ataturk if anything discouraged separate religious identities.