Head
In your circumstances my plan would depend on how much time I had and how much useful aeronautical experience I wanted to gain compared with mostly spectacular sightseeing.
Assuming you have the time and want to wring as much aeronautical experience you can out of the trip, it is worth planning to use a different means of transiting Nowra, Sydney and Williamtown in each direction.
My experience is that whenever Nowra Romeos are active, you don't get much choice but to follow the GA transit lane procedures described on the VTC and in ERSA. (Others' experience may be different.) I use the Nowra ATIS as the most current source of information on activation of the Romeos.
Therefore, if one or both of your transit days/times happen to be when the Nowra Romeos are active, you should be prepared to call for a clearance and follow the routes described. Conversely, if you want to fly the (spectacular) coastal route past Point Perpendicular, I'd suggest you do your homework and plan a transit on a day/time when the Nowra Romeos are inactive. If you happen to be transiting both ways when the Romeos are inactive, it's worth practising following the lane, anyway, at least once.
Victor 1 past Sydney is a 'must', as already noted and as you've probably already worked out. All the info is described on the VTC and in ERSA. Make sure you know how to obtain Sydney's ATIS info to set the correct QNH. Eyes out of the cockpit, particularly near the Heads and north. Lots of helicopter sightseeing traffic and amphibious aircraft tootling around the heads, northern beaches and Pittwater. Take particular care to know the bits of V1 during which you are not allowed to 'contour fly' the coast.
It's also worth flying into and out of Bankstown, at least once. It's pretty 'squeezy' up and down the lanes in and out of Bankstown, right up against and below Sydney Class C and Richmond Romeos, so you need to plan well and be well ahead of the aircraft.
Williamtown coastal is a must, but getting a clearance can take time. The boys and girls in blue have lots to do and you need to be prepared to orbit and various points prior to entry and along the coastal route. Fortunately, there's lots to see while you are doing that! My view is that one transit using the inland lane is also a must - for experience' sake - and it has the benefit that you don't need a clearance. But note the upper level of each chunk of the lane and the nearby elevations! Spectacular, but it can be very uncomfortable in a variety of weather conditions. (I haven't given the overhead lane a go yet. I'll add that to my bucket list!)
Enjoy!