Why is the part of the earth tilted towards the sun warmer? Which factors matter more?
The 5 factors you mention are not nearly as important to the effect you're asking about as another, more fundamental factor: time.

If you've read my answer to this other question, you should understand that all of the factors you mention would create temperature differences at different latitudes whether the Earth is tilted on its axis or not.

But because the Earth's axis is tilted, at some parts of the year the regions of the Earth tilted towards the Sun (in "summer") receive sunlight a greater proportion of the day than the regions pointed away (in "winter"). 

Not only that, because of the more direct angle of the Sun the factors you list mean that the regions in "summer" are heated better during the day than the regions in "winter". 
And this adds up over all the days of summer or winter until the Earth's orbit reorients the axis relative to the Sun.

Or even more succinctly, summer is hotter because the Sun is higher in the sky for more of the day.