Find messages - searches

hello,

I am trying to find out how to do two things.

first, how can I edit a search, say I created a very complex search and after 
some time discovered that I need to change a small thing, or perhaps just 
review the search conditions for some reason (for example to make it a filter), 
how (if) could that be done.

second, is it possible to create the next search: find all the threads (threads 
and not mails) started by a certain address (say me), this way I could track 
easily the replies to the list for threads I started.

as always, thanks in advance for your help in my quest for easier life :-) 
powered by Linux.

regards,
YB.