Question of many METHODs

Hello,

I have a question about HTTP Protocol.
I wonder if all of METHODs have been actually used (or
implemented?) because there are so MANY METHODs

[1] TRACE
  This function is like UNIX TRCEROUTE COMMAND?
  This is only for Debug?
  Is it useful?

[2] PUT
  Is this the same as FTP PUT?

[3] DELETE
  This is to delete files on a server?
  If so, isn't it a security issue?

[4] OPTIONS
  What the function is for?

A client (User Agent) must support all of these METHODs?
I do not like to implement METHODs which I rarely use.
As XTHML1.1-Basic will include a thin spec for a thin client,
there must be a thin HTTP spec which supports only necessary
functions.
I am thinking that above [1],[3] and [4] are not necessary.

Is there anybody who knows such a thin spec?
Any information or opinion is welcomed.

Sincerely,

-- Kojiro Goto
-- goto@isp21.co.jp