If patient opens/closes his eyes occasionally, caughs when suction is done (sometimes alone to spell out secretions) does it mean he's still in coma?

Yes: If your loved one is coma, and the reason for the coma is not anticipated to be permanent, you remain hopeful and vigilant for signs of improvement ( such as their eyes following your face and voice, and purposefully moving their hands or tongue). Coughing is a reflex and does not mean the person is conscious.

Coma vs vegetative: You are describing a person who has become somewhat responsive and therefor not actually in coma.. The patient is in a minimally responsive state, in which there will be times of unresponsiveness and times of minimal signs of responding to stimulation.