I'm not sure how you were able to generate all the tag mismatch warnings. I don't get any tag mismatch warnings.
The last three warnings will be fixed by using this:
PHP Code:
if ( !is_user_connected( id ) ) return PLUGIN_HANDLED;
instead of:
PHP Code:
if ( !is_user_connected( id ) ) return;
This is not how I would fix it but this is easier for you and it will work just fine. I won't go into detail since you didn't write the code.
The three warning 225 can be ignored. This is caused by poor coding but won't affect anything.