If you want to disable text selection on everything except on <p> elements, you can do this in CSS (watch out for the -moz-none which allows override in sub-elements, which is allowed in other browsers with none):
* {
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: -moz-none;
-o-user-select: none;
user-select: none;
}
p {
-webkit-user-select: text;
-khtml-user-select: text;
-moz-user-select: text;
-o-user-select: text;
user-select: text;
}