NFT preview card component challenge using Bootstrap

Hey Everyone! I am truly delighted to present my first ever mini project (Apart from those I have done in online courses) after learning basic Frontend!!

For the questions, here are a few which bugged me throughout the working session-

1. Should I rely on bootstrap completely for basic styling like justify-content, padding etc. instead of doing it with css?? In my project though, I tried to use bootstrap just for it's structure rather than styling.

2. Is there a way to have all hover elements (clubbing them) to have same properties as they were being repeated in my code a lot, like transitions, visibility, opacity etc.??

3. And do advice me based on my current work that how should I further improve in this field if I would have worked in a workplace with teammates, be it naming conventions, or using divs around anchors or any other that comes to your mind.

4. Also in general which units do you prefer when giving margins, padding when compared to fonts etc for better responsiveness.

5. For the media query I have set up, as the screen get's smaller it was getting worse to display the card, could you suggest something for it like which properties should I be changing

6. O ya, another one... (LAST I PROMISE) Can someone help me out with keyboard navigation. I have seen a lot of videos stating that website must be compatible with keyboard, but didn't find any one of great help

Thanks again!!