Can you be charged with a DUI of controlled substance without being drug tested or any other test?

Yes. Typically, if you did not provide breath or blood for testing, the officer will provide testimoney in support of his/her position that you were driving under the influence. Such as, smell of alcohol, blood-shot eyes, poor balance, slurred speech, etc. There is also a charge of Operating While "Visably" Impaired which is based solely upon the observations of the police officer. The issue now is, does the evidence or testimony the prosecutor has meet the burden of proof "beyond a reasonable doubt" that you were drunk or on drugs while operating a vehicle. If you had your own blood test done or have witnesses or other evidence that you were not under the influence, then you could get the case dismissed either by the prosecutor or a jury if they choose to go to trial.

Maybe. If the prosecution determines that enough evidence exists to support a criminal prosecution for DUI they can.and will. Evidence they may consider involves the driving observed, physiological exhibits like speech, eyes, coordination, etc. these factors are part of a DUI prosecution and be sufficient depending upon the drug(s) involved (if any) to support a criminal prosecution. If you were requested to provide a sample of your blood (drug/alcohol case) or breath (alcohol only case) and refused, you can be prosecuted for refusing to comply with implied consent, a crime that carries sanctions for your license beyond those of a normal DUI prosecution and enhanced punishment if convicted of DUI. You should contact a local DUI attorney and discuss the facts of your case and determine whether or not you need help.

You can be charged. Whether or not the State will be able to meet their burden of proof is to be seen.

Yes. It's called a refusal, which is more serious than a regular DUI.

Yes, it is your actions which result in the DUI. The various tests are only means of the prosecution gaining additional evidence of your guilt.