1. If you have original docs, just colour scan them and attach.
2. On immi website just search “attaching docs to an online application”. You will find answer.
3. As regards payslips, just do few e.g. one from start then middle of year then end same for next year. Attach group cert as additional doc.
4. For 887, no IELTS required.
5. Take photo from your mobile & attach.
Note. Nothing in the above written response constitute advice or practice of law. You should do your own research and can seek advice from experts. Best of luck for your application.