Leave it to Giu to point out what should have been so obvious to the rest of us, that your mast probably has too much rake in it. Double check with the Mac user groups (I think that your boat is supposed to have a little more rake than others but you may have too much right now). Drop a plumb bob from the masthead (using the main halyard). It should measure around 4-5 inches from the mast at the boom. This should also align your boom to be more parallel with the water line. Without a gauge it’s tough to get precise tension on the shrouds and stays – tighten them enough so there is no slack in the leeward ones when sailing in 10-15 kts of breeze. Your headstays shouldn’t “sag” off to leeward either. Another trick is to set your jib instead of the staysail which will also move the center of effort forward.
I noticed that you don’t have a traveler so you need to ease the mainsheet. A “little” weather helm is good. The opposite, lee helm is bad. I also see that you have tell tales on the luff of the main. You also want to put them on the leech. When trimming the main, you want the leech tell tales to stream back.
Is your staysail made by quantum? Sweet – that previous owner dropped some coin into her. Keep sailing and I hope to see you on the Bay real soon!
GeorgeB, s/v Freya