Anyhow I want to know that if we delete our posts ourselves, does it have a bad effect on our account and can we still get tagged or something or it is completely normal ?
losing your activity count or being demoted to a lower rank if you delete enough of your posts is the only thing I can think of that would negatively affect your account, though some members find what you did suspicious, or might ask some questions. just so you know, there are already members who have deleted enough of their posts themselves that their activity decreased, and nope they weren't tagged for doing it.