Did only one problem correctly, should I schedule a redo?
I got 1.5 - Redo and got 3 done. So yes, do it!
I did karat too. I failed because i did only one question but i did that question very well. The thing i can recommend you is, reschedule another one and try to solve questions as fast as possible. Don't care about readability or efficiency. Also study some data structures. I found as you are doing more questions they get harder. But many of the questions are simple in the sense they're mapping data from one collection to another. So study for those better ways to do things. For java i would say look for java stream api and how collections work. Such as count by, collect by etc.
Most likely yes. Which company/role? How far did you get on the second question?
For Glassdoor, just started the second question with telling the approach and interview was over.
Yeah, I would probably do the redo. You should shoot for getting two questions done. May be ok with being close to done on Q2.