rsync ignore owner, group, time, and perms

I think you can use the -no- options to rsync to NOT copy the ownership or permissions of the files you're sync'ing.

Excerpt From rsync Man Page

--no-OPTION
       You may turn off one or more implied options by prefixing the option 
       name with "no-".  Not all options may be pre‐fixed  with  a  "no-":  
       only options that are implied by other options (e.g. --no-D, 
       --no-perms) or have different defaults in various circumstances (e.g. 
       --no-whole-file, --no-blocking-io, --no-dirs).  You may specify 
       either the short or the long option name after the "no-" prefix (e.g. 
       --no-R is the same as --no-relative).

       For example: if you want to use -a (--archive) but don’t want -o 
       (--owner), instead of converting -a into -rlptgD, you could specify 
       -a --no-o (or -a --no-owner).

       The order of the options is important:  if you specify --no-r -a, the 
       -r option would end up being turned on,  the opposite  of  -a  
       --no-r.   Note  also  that the side-effects of the --files-from 
       option are NOT positional, as it affects the default state of several 
       options and slightly changes the meaning of -a (see the  --files-from
       option for more details).

Ownership & Permissions

Looking through the man page I believe you'd want to use something like this:

$ rsync -avz --no-perms --no-owner --no-group ...

To delete files that don't exist you can use the --delete switch:

$ rsync -avz --no-perms --no-owner --no-group --delete ....

Timestamps

As for the timestamp I don't see a way to keep this without altering how you'd do the comparison of SOURCE vs. DEST files. You might want to tell rsync to ignore timestamps using this switch:

-I, --ignore-times
       Normally  rsync will skip any files that are already the same size 
       and have the same modification timestamp.  This option turns off this 
       "quick check" behavior, causing all files to be updated.

Update

For timestamps, --no-times might do what you're looking for.

I think it´s easier to avoid the -a option

$ -a, --archive               archive mode; equals -rlptgoD (no -H,-A,-X)

and set only the options do you want.

If you like all options but not the modifications of user -o, group -g, time -t and permissions -p so you could subtract these four options from the archive equivalent.

$ -rlD

To delete the files on destination please use option --delete.

To your question: But I think all files will be checked - rsync can´t transfer/check only files that changed only by content.

I think what you are looking for is the option

rsync -r --size-only

from the man page:

--size-only
   This  modifies  rsync’s  "quick  check"  algorithm  for finding files that need to be transferred,
   changing it from the default of transferring files  with  either  a  changed  size  or  a  changed
   last-modified  time  to  just  looking  for  files that have changed in size.  This is useful when
   starting to use rsync after using another mirroring  system  which  may  not  preserve  timestamps
   exactly.

If you really want to delete files missing in the source dir use --delete