Actually if the editor did an initial screening to see if appropriate for their audience & then sent it out for Review - You have a very good chance of it being accepted. Frequently after a manuscript is Reviewed there are comments and suggestions for making it a stronger piece.... and yes unfortunately sometimes they will say not up to the level needed for this Peer Review Journal..... but always ask for Feedback in that situation.... because I would do re-writes and possibly send to another Journal.... Good Luck!
It is difficult to give a straightforward answer. A manuscript can still be rejected after it has scaled through initial screenings. The Editor may not necessarily be an expert in that specific field. As a result, the Editors take a decision on the comments and recommendations of the reviewers. Sometimes, the peer reviewer may not do a good job or thorough review or may be lenient and thus recommend acceptance. Another review of the same manuscript may be thorough and lead to rejection recommendation.