Those are fairly typical questions, and are essentially variations on this common theme:
- What's your biggest strength?
- What's your biggest weakness?
- Tell me about a time you've been wrong
They are all questions aimed at gauging how you handle criticism, whether you're realistic about your own limitations, and whether you're willing to learn/improve.
So when they ask you whether you've "ever received feedback on how you should improve", the correct approach is to make something up even if you never officially have.
Don't say something negative such as
"I was told I'm always late."
Instead, focus on something which demonstrates a willingness to improve without implying incompetence on your part:
My team leader once pointed out that the way in which I was accomplishing "x" in my code was not the most efficient. He described a different technique to me which I researched and then used to improve the performance of my code. As a result my page loaded Y seconds faster, which the users were thankful for.
That answer shows that:
- You know you're not perfect (no one is, although some people would like to act like it, and it's a big red flag for HR)
- You gracefully accepted (mild) criticism
- You took the advice to improve to heart
- You were willing to learn something new and upgrade your skills/knowledge/technique
Saying that you never received any feedback or advice to improve is - to them - essentially declaring that you're great, don't need to try any harder, etc. Instead have a couple of anecdotes ready to demonstrate that you're humble, willing to admit fault, learn, etc.
If necessary, make something up. You know that their purpose in asking that question is to gauge your ability to learn and accept criticism, so give them what they want. If you can't think of a situation where that exact scenario took place, adapt and improvise. Simply answering "No" will send the wrong message, even if it's an honest one.