Thanks everyone for the advice, got this done by 6:30 this arvo in the end so not too bad considering I started at noon and had no idea what I was doing - well, that's a bit unfair, I did have the how-to in this thread from UK
All in all not a hard job, even for a novice like me. The only worthy mention of course is the tension adjuster which freaked me out when the thread ended on the tensioner plug and this thing pushed the bolt away from the well - that was the only 'oh no, that's not in the how-to' moment.
But you're right Maka due to the spring and the groove in the tensioner adjuster I simply aligned it back with the pin on the roof of the well and it screwed back in under tension. Hopefully that's all it needs. Evgeni your way sounds awesome, didn't know that the actual plug can be separated into two bits as well. Mine looked like the two bits were held together at the thread with Loctite, definitely spun together and managed to tighten the whole plug assembly without breaking the seal. I'll keep an eye on it though if it leaks it may be worth pulling it out and replacing those O-rings and clean the filter as you say.
Here is what the tension adjuster looks like loose:
And the well without the tensioner - you can see the pin on the top, align this with the groove in the tensioner and the thread should be ok to wind back on (I hope):
In the end, my tensioner plug was definitely loose so I'm glad I took the car apart today, definitely leaking from there, plus at the lower mounting bolt for the power steering reservoir mount (the weird one that has a smaller bolt than the actual hole, and goes straight through the oil gallery). Anyways I tightened it all up and will keep an eye out. Not a hard job, just a bit scary but all good in the end.
A couple of after shots:
Warmed the car up and went for a quick spin. No leaks so far and the car idles fine. The big test is tomorrow when I head to work using 3 motorways
Oh and the bonus is I found out why my car is squeaking - if you can call having to buy and install new bearings a bonus...
Cheers everyone.