Yes, those with diabetes have a two to fourfold risk of developing Coronary Artery Disease (CAD) and the extent and severity of CAD depends on the duration of diabetes. Whether the extent of coronary disease will warrant a stent or other treatment depends on the results of the coronary angiogram.
As to improving the chances of not needing stents or other intervention, while it has been shown that intensive lifestyle modification and medical therapy helps to prevent and mitigate the progression of diabetes, and also helps in modifying surrogate markers such as lipids (LDL, HDL) and hypertension etc to a favourable profile (and therefore less cardiovascular events) this may not have much impact on established CAD.
You may want to refer to a most recent trial that followed up diabetic patients for upto 9 years(see below). This is only one of many trials available in the literature. In general, we need to look at a time span of from 4-5 years and sometimes up to a decade or more for lifestyle intervention to make a difference however.
As for heart stents, the blood thinning therapy can be cut short from 1 month to 6 months based on the need for surgery with many current generation stents.