Are there any alternatives to insulin injection?

Yes. For type 2 diabetics whose body still produces its own insulin, one may be able to control blood sugar with pills, injectables that are not insulin, diet modification, daily exercise and achieving a healthy body weight. As type 2 diabetes progresses, however, Insulin may be required. In type 1 diabetes, Insulin is always required.
Kind of. If you are requiring Insulin injections another alternative to multiple daily injections is an Insulin pump, which is still an injecton but only requires changing infuson sets through which the Insulin enters the body under the skin every 3 days. Another option is the i-port® - an injection port you inject the Insulin through, but like the pump needs to be changed/reinserted every 3 days.
Sometimes. If a patient has type 2 diabetes, treatment consists of diet and lifestyle changes with diabetic medications if needed. Diabetic medications include pills, non-insulin injectables, and Insulin by injection. It depends on what works for an individual patient. There was an inhaled Insulin but it was not used much and was then removed from market. Type 1 diabetics will need to use insulin.
Yes. People with type 2 diabetes can improve their diet and use exercise to help keep blood sugar normal without Insulin or other meds. Those with type 1 must take Insulin but can use a pump rather than injections.
Yes. Patients with type 1 diabetes require insulin, sometimes it is given with an Insulin pump rather than injections. Type 2 diabetics, may be controlled on oral medications, but many of them eventually require insulin. Some studies have been done on Insulin given by nasal spray, but this is not as reliable in terms of knowing how much you are getting.
It depends. People with type 1 diabetes (insulin dependent) will need Insulin provided in some manner. Type 2 diabetics (non-insulin dependent) have many options. Diet, nutrition, and exercise are critical. It's essential to maintain a normal body weight. If needed, neurotransmitter therapy using the neuroresearch protocol is an excellent approach that can eliminate the need for Insulin in type 2 diabetics.
Yes. Once it has been determined that you need Insulin (either type i or advanced type ii with pancreas failure) usually you will be started on insulin, usually a long acting and a slow acting. A more advanced option for a cost can be an Insulin pump that continuously pumps the Insulin in your body at a designated rate. Some even measure the sugar in your blood to match an appropriate rate.
Not really. As far as Insulin forms go, there was an inhaled version of Insulin that never really took off. Practically speaking, Insulin is really only useful in injectable form.