Asking for opinions

Do you have any idea/comment on the plan?
    What do you think of this magazine?
    What's your view/opinion/idea of this plan?
    Could I know your reaction to this plan?
    Could you suggest some way of losing weight?
    What would you say about UFO?
    What shall I do for the party?
    Shall we start now?
    How do you feel about my new car?