Hi,
I just complete signing s&p yesterday of buying first house too (subsales, first owner buy from developer for investment, basic house).
Hope this can enlighten you.

1. Yes, if not confident try to negotiate to lower down the deposit. My house agent ask for 3% and we negotiate to 2%, both party agree with 2%.
2. what kind of interest ? house loan interest ?
3. Booking form (agent will fill for you), alongside with your cheque number, amount, address of the property, and clause (if owner cancel to sell or your loan rejected)
4. if you feel uncomfortable yes. but most important thing is checking whether your house agent (agency and the person) reliable or not.
5. Need to do research for the agency. When you talking to the agent, see their body language, trust your instinct! Good agent will be easily to look for if you need assistance, not avoiding your call, keeping their promise, and always following up.
6. Normally stated in booking form clause, owner will need to return 3-4x of your booking deposit if seller change their mind.
7. Stated in booking form clause too, for example : subject to 90% loan by 3 banks, means you will have to bring at least rejection letters from 3 banks to get your deposit back.

Tips :
Ask a lot of questions to your agent regarding the house (cukai, maintenance fee, bills, rents if any, warranty for defect, discount, etc).
After put deposit, prepare all the document and submit for loan to several banks.
Get ready for all legal fees when you do s&p and loan agreement.