did you read this FAQ?
http://webyog.com/faq/content/16/4/en/do-i...with-mysql.html.
I do not understand "Can I use any of the PHP commands to do things ...". You use SQL commands, not PHP commands to read or manipulate the database. SQL commmands may be embedded in any language that can connect to MySQL. Not Only PHP, but ASP(.NET), RUBY, PERL, C/C++, JAVA, Delphi(Pascal). The 'parent' language does not really matter - it is the SQL that does.
Am I missing something?
1)
To select the no. of rows:
With Notification service you can "SELECT COUNT(*) FROM a_table" or "SELECT COUNT(some_column) FROM a_table"
2)
This "Any way to list all rows added to a table since the last time the notification was run". You can have a strings column and notifcation can exectute basically 2 statements
SELECT ... FROM a_table WHERE some_column <> 'seen_before'.
UPDATE a_table SET string_column = 'seen_before' {WHERE string_column <> 'seen_before'
(don't forget to mail the results of the SELECT statement)
But you will have to tlet the Nofofications job wirte to the database You may also use a TIMESTAMP column a similar ways
All those questions are SQL questions basically if I understand correctly.