Welcome to Over50sForum! The site for people over 50 to chat, make friends, discuss, share, and generally be part of something that's fun and friendly :)
I'm guilty of using 'just' at times in emails. Not so much in speech, as I am aware it can sound a bit manipulative.
The benefit of asking someone if they would be ' willing' to do something is interesting though. My go to phrase is " I was wondering if you would mind?......."
I'm definitely going to try using 'willing' next time.