Clicking the [ +/- ] button takes you to the Develop module but doesn't make any changes. You can hover over any badge in the Grid View and it will tell you exactly what it means.
"Well Lightroom will start automatically editing all the pics again. I want them to stay the way I edited them." I have no idea what you mean by this. Unless you do something, Lightroom does not do anything. If you are that paranoid about it, create a Snapshot of each image after you finish it - that way if something unexpected or accidental happens, you have the finished version saved.