For the greeting, just add the following line to your remotes (Alt+R):
on *:JOIN:#mychannel:if ($read($scriptdirgreet.txt,s,$nick)) msg # $v1
Then make a file in the same folder as the script, name it greet.txt, and fill it with lines of the form "nickname GREETING", ex.:
toy{T} Hi, $nick $+ , sweet thing... blah blah blah
For the seen script part, download one from the list of sites above. Also, if your channel sees a lot of traffic (joins/parts) you might want to get a more efficient greet script than the one I just listed as well. I only posted it for simplicity sake, since it's an easy one-liner.
