Depends on control. For the most part, if your diabetes is under good control and you are on a stable medication regimen it shouldn't change your risk much. If you are very Insulin dependent, managing your Insulin dose while you heal and regain your appetite can be a bit tricky but still very easily accomplished. Your risk shouldn't meaningfully increase unless your control is very poor or you have heart disease.
Depends. Diabetes is a risk factor for post-operative complications, especially infections. This is especially true if your diabetes is not well controlled.