You can't delete journals. You can delete/edit comments and entries.
This current system doesn't work like that (journal deletions). People can just 'lock' journals. You'd have to delete from the database.
For the next version though, journal deletions 'should' be accounted for otherwise there would be database errors if one somehow tries to view the journal of a deleted user. (Has already mentioned this.)
You can keep selected usergroups out. In that file usergroups 1, 3 and 4 can't view journals. I'm not sure if I added usergroup 8 there. On my server usergroups 8 and 10 are added to the 'no-permissions' list. I have my code thus;
PHP Code:
//if user is NOT registered / Email not confirmed / (COPPA) Users Awaiting Moderation THEN cannot CREATE journal.
if(($bbuserinfo[usergroupid] == "1") || ($bbuserinfo[usergroupid] == "3") || ($bbuserinfo[usergroupid] == "4") || ($bbuserinfo[usergroupid] == "8") || ($bbuserinfo[usergroupid] == "10")){
//redirect
$goto="index.php?s=$session[sessionhash]";
eval("standardredirect(\"".gettemplate("redirect_noaccessjournal")."\",\"$goto\");");
Just edit that for whichever usergroups you don't want to view the journal feature. For example, by default, 8 = 'Banned by Moderators'.