If it is relatively simple text only, I prefer it on the computer (in a simple text editor, not a word processor where you are distracted by formatting).
But I often use a mind map on paper to generate and exhaust thoughts about a subject, including blog posts.
One of the most salient features of our Tech Hiring culture is that there is so much bullshit. Everyone knows this. Each of us contributes his share. But we tend to take the situation for granted.
For 3. ("Brainstorm on paper"):
If it is relatively simple text only, I prefer it on the computer (in a simple text editor, not a word processor where you are distracted by formatting).
But I often use a mind map on paper to generate and exhaust thoughts about a subject, including blog posts.
Mind maps are also a good thing to have in your toolbox. I use paper when I feel stuck on my computer. If I don't, I don't use it.