Many people have commented on this already, but I'll just second their opinion. There
really is no reason to just send your abstract/manuscript to that many journals for a pre-submission opinion. In fact, many journals (if not all) have a policy that you may not have your paper submitted to another journal (I image that would be the same for the pre-submission process). What you are doing is putting the system under pressure. Editors are very busy with screening papers,
you should be the one who decides what journal fits best with your manuscript,
you should be responsible for that decision. The reason that there is a pre-submission option, is to allow you to ask the editor whether they agree with your choice so that you can go ahead and format the paper along their guidelines.
If you are not familiar with the submission process, you should just go to the respective journal and read their editorial policies. Here are the ones for Nature, I don't suggest you submit there, but it will at least give you a good basis to start from:
http://www.nature.com/authors/editorial_policies/index.html