You can see all of them except the object at -67 degrees. However, the object at -40 degrees will only ever be at most 7 degrees above the horizon which is not an ideal position for getting good quality views: you are looking through the atmosphere at a very shallow angle which degrades the view you get. The longitude is unimportant: an object may not be in view at a particular moment but it will come into view at some point in the following 24 hours. That may be in the daytime but you will be able to see it at night at some point during the year.
As for calculating this, recall that the celestial sphere is basically an extension of the coordinates used on Earth - the poles are directly above the poles on Earth, as is the equator. The only difference is that longitude is quoted in hours (as right ascension) rather than degrees.
If you are at 43 degrees north then the point directly overhead (the zenith) will be at +43 degrees declination. Looking south, assuming the ground is perfectly level the angle between the south horizon and the zenith will be ninety degrees. So the furthest south you can see is +43-90 (-47) degrees. Anything further south than that will always be out of view.
