Should I remove a coauthor if he did something detrimental to the project?
This is a tricky one but you might just have to bite the bullet and keep his name on the paper, making a mental note both not to work with him again and being careful about who you name as co-author.


  one of my coauthors had done some bad acts against the project
  (related to the paper) in the past and now I want to delete his name
  from the author list.


But have these acts impacted on the quality of the paper? It sounds like they have affected the project but not specifically the paper. This is a similar criticism to people complaining against the internal bickering and politics of e.g. software development which affects how software is made, yes, but doesn't necessarily affect the quality or accuracy of the overall output product.


  Meanwhile it should be noted that his collaboration with study had
  never been scientific and I wrote with negligence his name.


So he did make some contribution? What was this contribution? Conceptual? Literary in some way? I would doubt that you included his name with negligence at the time you did so, but now it seems negligent in the light of new information. 


  However, my big concern is now that removing his name might be
  un-ethic!!


I think it would certainly raise some questions that might be difficult to answer without possible repercussions on yourself. I would grit your teeth and let the paper go through further revisions, it sounds like it's too far down the line to remove a co-author's name, but be careful who you include - and why - in the future. Academia is a learning process in more than one way.