Mr.Johnny, yes, you can fill in the visa application form using handwriting. You can apply in a group and appply for China visa on behalf of them, however, the visa application form should be signed by themselves. You don't need any proof or letter from them, but you should take their original passports and other requirements for visa applicaiton

Thank you for your reply.Do I need to fill any form for group apply when I submit the visa application with their passports.since I know in KL china embassy will limit 4 application for 1 person.