Depending on the editorial system, it could very well be that reject & resubmit comprises all cases where the paper was neither accepted as it is nor finally rejected. So, in your case, it could just mean that the paper was rejected in its present form (because you need to make the minor revisions requested by the reviewers).
Of course, if the editorial system offers finer-grained status messages, it can also mean that the editor sees more need for revision than the individual reviewers do or estimates the revisions requested by the reviewers to be more substantial than the reviewers did. The editor’s letter may give you more information on this.
Either way, I would not worry too much about it, improve the manuscript as much as you can, and resubmit it. This way has almost certainly the lowest expected waiting time to a final publication.
With a new submission, is it possible that the editor does not send the manuscript to the reviewers but decides by him/herself?
Yes. If you replied to the reviewer’s comments in a satisfactory manner and did not insert a lot of new material, it may very well be that the editor expects that a new round of review will not yield any further input and accept the paper. Of course, the editor could also reject your paper without further review if they think that you did not even attempt to address the reviewer’s comment or similar.