I can try and answer this one for you.  It sounds like the boat has very basic rig controls, as such i would not worry about changing too much whilst you are out sailing, the difference marginal changes in control and rig set up make pale to insignificance when you sail the wrong way up a beat.  The kicking strap tension will depend on the sheeting arangement for the mainsail.  I would guess on a GP that age it has rear transom sheeting, if this is the case i wouldn't use huge amounts of kicker.  As when you tighten the sheet you are tightening the leach of the mainsail.  I wuld use just enough so the boom doesn't sky as you tack and so your leach tell-tales flow nicely off the back of the sail.  In terms of outhall, i would have this fairly tight inland in light winds.  having it too lose will mean you have too much depth and the wind will strugle to move across the main.  I would also check you jib sheeting angle before you set off, ideally you want the genoa leach to match the profile of the main when close hauled.

 

I am sure someone will disagree with what i am saying but thats how i would look at setting the boat up.

 

For me the most important thing whilst small lake sailing is getting a good clean start and sailing the right way up the beat, keeping my head out of the boat and looking for wind shifts.