exif manipulating utility?

After a trip I collected photos from several friends. Some of them have the
wrong file time stamp. Some also have wrong exif dates (not adjusted for
time zone). Plus, I created jpg files that are actually text description of
the location, and I want these descriptive jpg to be displayed in the right
order among the photos.

In order to view these photos on various platform (windows, iphone, ...) in
the correct chronological order, I need to be able to (1) edit the exif
dates in individual jpg file and (2) bulk copy exif dates to file dates of a
bunch (3) copy exif dates into filename. This is because many photo viewer
sorts by file name, some sorts by file dates, and a few can sort by exif
dates. I want to name the files and set the file time stamps so that no
matter which of the above fields are sorted, they would be displayed in the
right order.

Any suggestion on freeware for windows that can do the exif manipulations?