Software dev clueless in graphic design here. In your opinion,

That entirely depends on what you're building for and why. In general, it's probably best to stick with sans serif fonts.

For some examples, I believe Microsoft uses Segoe UI for most of their stuff and Apple now uses San Francisco.

Literally anything sans-serif that is highly legible when its bold or regular.

Eyes generally go to icons first
Then bold
Then regular
[depending on layout]

Anything with movement or animation when it is first introduced will have eyes on it first.

>>249134
PT Sans or Ubuntu font

But, the pt sans is so slow

>>249134
I really enjoy using Futura, Helvetica and/or Raleway.

>>249993
>pt sans is so slow
??????