Depending on exactly where you live, you could do jasmine or a native honeysuckle for flowers. Grape vines are traditional for a reason, as well. Trumpet flowers and wisteria are invasive in my area, and I would avoid them, but you could check whether either is a good option for your area.

Maybe! I don’t know enough about making champaigne to be able to say.

The fresh fruit should work. Are you asking if a bottle of wine would give you yeast? The answer is generally no. Most wine has stuff added to stop fermentation. It may also be filtered to remove yeasts, etc.