Since no one else has responded yet, I'll do what I can. The high pH is not good for tomato plants which prefer slightly acid soil and tolerate neutral. At that high of a pH some nutrients become pretty much unavailable to the plant, including iron, manganese, zinc, copper and cobalt and calcium and magnesium to a lesser degree. I know that lack of iron tends to cause yellowing and lack of calcium is one source of stress to the plant, and is associated with blossom end rot. Whether this would cause fusarium wilt like symptoms is beyond my "scope of practice," but maybe someone else will jump in here now.
You can mix peat moss into your soil to help bring the pH down. Or especially since your soil is also low in nitrogen, look for fertilizer that's made for azaleas and other acid lovers, helps fertilize and acidify.
One way to find out if the high pH and low nitrogen is causing the problem is to fix those things and see if the problem goes away!