Etmsreec, as I understand things, the general rule is that aerobic activity will utilise blood glucose as an energy source and hence lower it, while anaerobic exercise on the other hand can cause a flood of stress hormones (largely cortisol) into the body that increase the liver's production of glucose and reduce the muscles' uptake of blood sugar, therefore often leading to hyperglycaemia.
The problem for diabetics is knowing exactly where the line between aerobic and anaerobic is. If, for example, you cruise along steadily at a moderate pace for 45 minutes, then you've worked purely in an aerobic capacity; however, if you were to throw in a few flat out sprints as well, then you've done a mixture of aerobic and anaerobic and, in this situation, I know from my own experience, it can be incredibly difficult to plan for or to predict exactly what the outcome will be for your glucose levels.
My guess is that the elevated glucose level that you experienced is down to the hormonal response that I outlined above. It's certainly something that I've experienced frequently and not only with swimming but with other forms of exercise.
As for your other point, as a personal trainer I find that most clients (non-diabetic) complain more about muscle soreness TWO days after an intense workout rather than one, so what you're describing as a diabetic is not really so different. There may well be some physiological reason why a diabetic would experience muscle repair slower than a non-diabetic but it certainly is not my own experience and I've had Type 1 for 27 years. The best advice I can offer towards avoiding DOMS (delayed onset muscle soreness) is to make sure you stretch well immediately after exercising in order to avoid post-adaptive shortening of muscle fibres and then to eat some carb-rich foods as soon as you can to help replenish muscle glycogen stores.
Hope that helps