Income tax rates go up like this (purely example) 0-20000 - 10% 20-40000 - 15 40-80000 - 20 80-100000 - 30 100-150000 - 40 150000+ 45%

If you make 75000 in this example, you’re taxed 10% on the first 20k, then 15% on the next 20k, then 20% on the remaining 15k, so 2000 + 3000 + 4500.

Lowering the top rate of income tax means that the people who earn more than whatever the limit is (150k in this example) pay less tax. Generally, the consensus is that the rates should shift to the higher income rather than the other way around.

Quantitative easing is the government buying up bonds to support their value. If everyone stops paying their mortgage, the economy tanks because the bonds that represent those mortgages go to zero. If the government promises to buy some them in spite of the zero value, the value is propped up. The people who benefit, by and large, are capitalists (those who make their money from already having lots of money ie wealthy). But it makes the cost of loaning money lower, so it becomes easier to get a loan, which combined with limited housing leads to an increase in sale prices of houses.