What period are you especially interested in? England/Britain governed Ireland wholly or partly for about 800 years and things changed a lot at different times. I'm most comfortable with the period just before independence (say after 1870) if that helps.
1900-10 were probably the best period of British government in Ireland's history. The government introduced a range of reforms that were intended to develop the country while conveniently undermining support for nationalism and radical politics. The 1903 Land Act accelerated the existing state policy of providing government loans to tenants to buy their holdings. This process (which began in 1870) was one of the most important developments in Irish history. It meant that, unlike most under developed societies, Ireland experienced reasonably peaceful land reform mostly before independence. There were sporadic violent protests by landless men during this period but the country was comparatively quiet.
The government also invested in education and passed a Universities Act in 1908 which incorporated Catholic interests. There is a debate about whether the government actively promoted Catholics in state jobs but certainly Protestants Irish remained over represented in senior positions in the civil service, police and professions.
Ireland remained a poor country and social innovation throughout the UK was disproportionately important. The introduction of the old age pension was hugely important as it gave elderly people a source of income for the first time and turned them from a drain on their families to an important source of money. The state never did enough about the awful poverty in the west and un the Dublin slums which were among the unhealthiest places in the entire Empire.
In terms of security, this was a fairly peaceful period and the police tended to manage on their own unlike in precious decades. It is interesting that the most ferocious opposition to the Trade Unions came from Irish nationalists like William Martin Murphy rather than the British state.
World War I brought a substantial increase in state surveillance and censorship. This was common to the whole UK but the response to the 1916 Rising was extraordinarily severe. Following the suppression of the rebellion, Martial Law was declared and thousands were arrested, many of whom had no role in the Rising. The executions of the leaders was drawn out and added to war fatigue and frustration at the lack of political progress radicalised the public.
The War of Independence went through several phases becoming steadily more vicious. The most notable British atrocities included the burning of Cork and the massacre at Croke Park on Bloody Sunday. More regular was the policy of reprisals for IRA attacks by destroying creameries or other public buildings. Under the Restoration of Order in Ireland Acts the authorities had extended powers of arrest, censorship and control of meetings. Martial Law was not declared through out Ireland however.
In summary, the revolution was not a response to immediate oppression. Things in 1914 were probably better for a lot of Irish people than they had been. Contemporary sources refer to political problems but both Unionists and Nationalists were optimistic about the country. Nationalists believed that Ireland could do better on its own and wanted a stronger Irish identity.