My experience is only with observing these boats, I have an O'DAY Day Sailer II which is not all that different from this ALCORT sailboat. I'll echo the comment above to ALWAYS sail with the mainsheet in hand, BUT I would not hesitate to use the supplied camcleat to hold the tension of the mainsheet, just ALWAYS keep the sheet in hand to allow quick release if a gust of wind hits. I have always sailed my DS II that way, and a 12' O'DAY Widgeon before that and never capsized. I have had a few close calls... sort of... but no worse than a little water coming over the lee side!
ALCORT was a well-respected builder and they seem to have built a lot of these SUNBIRD models, so she is a popular boat! I suspect that in the unlikely event (If sailed like the CB boat she is!) of a capsize, this boat would float pretty high on her side, making it not too hard to right her by standing on the centerboard. But the best way to recover from a capsize is to never let it happen in the first place.
Do not be afraid to sail without the jib if it is windy, or until you are used to the boat, just raise the centerboard a little to reduce the weather-helm (tendency for the boat to turn into the wind while sailing) A little bit of weather helm is a good safety factor, but too much is tiring and slows the boat down.
Unlike the SIREN 17 or Gloucester 16 (AKA: Newport 16, Lapworth 16, Capitol 16) the SUNBIRD does not have any ballast. The SIREN has a 100# steel centerboard, and the Gloucester 16 has either a ballasted keel or a heavy centerboard (100# plus, as I recall). I would not let that fact scare me away from the Alcort Sunbird.
The name of my boat (SUNBIRD) should not be confused with the Alcort sailboat, I just like "bird" names and my DS II is bright yellow!