[HELP] Oman Car Insurance claim

Hi..

I have a Honda Civic 2009 model which is still under comprehensive (full) insurance by Oman Insurance Company. I live in a very congested and crowded area in Doha, so every week I found a new scratch in my car. I never claim the insurance for repaint since I bought the car from Domasco coz I know if I repaint the scratch today maybe next week I will get another one due to the very congested parking, so better wait until it fully scratch or the car involve in some accident and claim it in one time. Now the time has come, someone broke my windshield and I need to replace it. I'm thinking of claim the broken windshield to be replace together with repainting the car which is also full of scratch now. Maybe someone can advise me:

1. If the body scratch and the windshield broken and we don't know who did it can we claim the insurance to repair all at the same time?

2. And what should I explain to the Police when I ask them for a letter since I don't know who did it?

3. I heard that the procedure of claiming an insurance is we need to open a file for QAR500 per claim then after repair again we need to pay 30% of total cost of repair, is it true?

Appreciate your kind advise, thanks