How is papal audience each Wednesday?

In winter the Wednesday audience is held in the Papal hall, adjacent to St Peters. The info is easily found on Google. The hall only holds 6000 so if you don't have a ticket, it's unlikely you would be able to get in. Pope Francis is hugely popular. It usually begins at 9, but since it's open seating, people with tickets begin to arrive when the doors open around 8, to get the best seats.

Is it interesting? That's very personal. As a Catholic, I found it so. There was a speech, delivered in multiple languages, followed by a blessing. Note that this is not a Mass.

it says for tickets,
Request forms must be sent directly to the Prefecture of the Papal Houshold:
Post : Prefecture of the Papal Household
Vatican City State, 00120

Othewise, "With or without a reservation, tickets must be collected the day before the audience from 3pm until 7pm. Tickets can also be collected on the day of the audience from 7am until 8:30am."

"In the summer months when there are more visitors, guests will arrive up to 3 hour in advance to ensure seating. Seating is first come first serve. Even if you have a ticket, you are not guarunteed a seat."

Is it a good idea to get ticket at 7am without reservation? what is the chance? it seems to me as long as I can appear at 7am, i can collect a ticket even without a reservation. Am I right?

Sure
But you are still not guaranteed a seat

Do I need a seat? Just stand there and listen to the Pope. Is that possible? what is the advantage of seat?

Since this is winter, it will be held in hall that holds just 6000
Ticket or not, once those seats are filled, that’s it
Are you feeling lucky?

What is your reason for doing this? Just to say you did or are you truly a papal fan?

EXPERIENCE. it is all. Nothing to do with the faith. So what should I do? send the filled form to Vatican now? or just bet on luck by arriving at 7am at Swiss guard gate?

Well you've had the situation explained. Without a ticket you won't be admitted. There is no guarantee that any tickets will be available that morning. Just how badly do you want to see the Pope?

I will send the form soon. Do you know how quick they will respond? and how will they respond? will they send the e-ticket to me by email? or mail a ticket to me?

I find this Please send this form by fax, post or email

in your 4th question up, a couple of hours ago you quote how the ticket is given to you. That should provide the answer to your question a few minutes ago,

You also know how to send the request, by fax, post or email.