To add to Chacha102's answer and also directly answering the third question:
You can apply various filters. Besides "wiki" they are: "hasaccepted", "closed", "answers" and "votes". There is also "user", but it is not so interesting in this context.
There is also a way to filter for a particular tag, the "[tag]" syntax. E.g. [perl] to only display questions tagged with "perl".
Examples (enter in the search box in the upper right on any page):
This example is also an answer to the third question. To list highly voted Community Wiki (CW) questions that have not been closed (100 votes in this example - result takes up 2 pages for Stack Overflow):
wiki:1 closed:0 votes:100
To list CW questions that have not been closed:
To list CW questions that have not been closed, have at least 7 upvotes and no accepted answer:
wiki:1 closed:0 votes:7 hasaccepted:0
To list CW questions that have not been closed, have at least 3 upvotes and have no answers:
wiki:1 closed:0 votes:3 answers:0
To list CW questions that have not been closed, and have at least 12 answers:
wiki:1 closed:0 answers:12
To list CW questions tagged with Perl that have not been closed, and have no answers:
wiki:1 closed:0 answers:0 [perl]
This can be expressed as URLs. E.g. for the third example:
These filters were described in an old Stack Overflow blog entry: Stack Overflow Search – Now 61% Less Crappy. The filters are documented in
/search and are more up to date, e.g. http://stackoverflow.com/search for Stack Overflow. There is a new filter:
intitle ("questions with specific words in the title").