For flowers and insects you need a macro lens, and be able to get
to ~6 inches/15cm from the front of the lens (50mm).

No film P&S gets that close.  18" with a 28mm focal length, maybe.
No good for insects.  OK for a complete rose bush.  Even if you got
that close there is no way to frame the shot.

Choices are

o Digital P&S with a good macro capability - maybe
  with vibration reduction.  I don't know of one that
  goes to 28mm equiv. at the wide end, most seem to stop
  at 38mm equiv. or so.  Maybe a complementary WA film P&S.

o Film SLR with a 28-105 zoom.  The macro capability on these
  lenses may not meet your needs and you may want a separate
  macro lens.

o Digital SLR, as above.

Flash is a good idea for macro because it steadies the shot and
darkens the background.  A bit of work with a coat hanger and some
white cardboard makes a diffuse reflector that will make for very
good macro lighting using an on-camera flash.

Digital is the only way to go for insects.  There are some things
digital does so much better it's not worth thinking of using film:
figure you catch the bug just right in maybe one in twenty or
hundred shots - with digital you know you have a keeper and
can move on.  Film can be _very_ disappointing unless you have
moribund (or fresh frozen) insects.  All the great insect
shots of the past were done with chilled insects.

Digital might be grudgingly acceptable - you can take the
camera in to the drugstore for prints, same as for film.

Figure $170 for an 'insect cam'.  I have, and like, a Canon
A520 (or somesuch). It can take close-up lenses for getting
_really_ close; also for getting close with a longer zoom which
you be farther from the insect with less chance of scaring it
away.

Figure another $180 for a wide-angle film P&S of your choice.