Who really needs to select 0.5 seconds in the timeline ?

Sometimes I need to review just a small section of my slide. I can't expect Storyline to read my mind when it's my mistake and when it's not. 

It's never happened to me to select by mistake. Just a brief click is necessary. If you linger with your finger on the click then you're not doing it right.

You can change the responsiveness / sensitivity of your mouse by going into your mouse settings in Windows.