Rails said..
Someone is going to say WA, but its full of sharks and kooks
alva beach f - crocodiles/box jellys - but hardly seen
don river mouth f - crocodiles/box jellys - nah... same as Alva
mackay town beach f - crocodiles/box jellys - nah.. plenty of room
somewhere north of yeppoon f crocs/sharks - true!
1770 f/w - Phil McConachie - nuff said
DI f/w - sharks - correct
Noosa river f - very small, crowded - kooks
cotton tree f/w - strong current/tides/sharks/crowds - for real men!
currumbin f/w - crowds/surfers - for tourists
flat rock w - localism/sharks - correct
woolgoolga w - localism/sharks - don't leave anything in your car!
fingal bay f/w - sharks - correct
nobbies w - sharks - nah safe as houses
caves beach w - sharks - occasionally (see "Shorty" with his Naish kites)
merimbula w - sharks/J Smythe/localism - and fishos with huge hooks.

and adding some more beyond Merims...

Lakes Entrance - sharks and sharks near the lake entrance itself. Safer up North towards the camping grounds, lower tide
Metung (inside the lakes) - awesome pub and deepest point in the lake, plus great lake style kite surfing
Loch Sport - worth a check, flat water, agro boaties, but nothing in off season
SeaSpray - awesome but HUGE wave spot. Huge tides too. Pick a relatively calm day
Waratah Bay / Sandy Point - best spot in the world! Flat as, plenty of room, try some land kiting even. Check out the local grub and cafe, which is owned by a famous kiter (no names)
Venus Bay - awesome wave and freestyle spot, lots of tourists though
Inverloch - same as Venus but monster waves
Kilcunda - another great open water spot, but beware of rocks further north on low tide.
Phillip Island - take your pick and wind dependent. A great flat water spot is left of Ventnor on high tide. Sharks do cruise up and down the channel though and dolphins
Cat Bay - Awesome waves and surfers if going of. Best to kite way back into the bay more
Summerlands on the northern side - great waves, sharks but very seldom
Penguin Parade - great waves but bay maybe too small for a kite session
YMCA / Smiths Beach - great surf spots, but maybe too small for kites
Woollies / Woolamai - perfect for kite surfing, waves and waves everywhere. no flatness here. heaps of surfers
Tooradin - on the way back to Melbourne it's worth a look. Low tide is best and winds can be iffy with the shape of the bay, but best with a S-SE above 12knots
Other spots worth checking...
Merricks Beach - longboard heaven here
Point Leo - rocks and surfers
Gunnamatta - surf heaven and similar to Woolamai
Portsea Back Beach - ditto
Corsair - awesome kite spot with choice of Northerly or Southerlies, but best on a N-NE. Bit gusty, flat and waves

And from there take your pick along the bay all the way to Altona / St Kilda

You're going to love it.