The search function is good enough as it is.
The 3-character limit isn't that big of a problem at all. It only is for some special/rare cases. But then again you can use some tricks: for example instead of
ink ->
"ink "
Search results highly depends on what you search for. In my experience, many people search for the wrong thing, either too specific, or too non-specific.
Limiting search result to latest x threads is very bad. Many topics are old and in old threads.
Sorting on relevance/importance isn't possible without a quoting system for each post. Even then, this kind of system isn't fail-proof.
Using the Patchou's FAQ is good if it was constantly updated. Even so, it doesn't contain many plus! related problems, or isn't detailed enough for the complete n00b. Also, this messageboard contains more then just the specific plus! stuff...
Even in T&T there are (sometimes) things that you want to search for.
Creating a big FAQ is very very intensive work. Although it will be a solution for many people. But it needs to be maintained constantly by very responsible and organised people (and not too many people) who also know a lot about all the problems given and have the time to test/verify/comment/etc... Creating/maintaining such a faq is a full-time job. Don't underestimate it...
EDIT: also see
http://shoutbox.menthix.net/showthread.php?tid=24...d=240412#pid240412
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