APS62 1.0.0

I have two questions for the forum members, pls advice:

1. REAR CARRIER  (page 4 & 5) : Can I  use four 4* dia 8mm SOCKET BOLTS (save / Part No: 02-page 4), instead of indicated four 4 * dia 8mm FLANGE BOLT (part / No: 02 - page 05), with the same length ?
2. REAR CARRIER BASE (page 01): What's for the rubber bracket Part / No: 06, is that also for the U locker support as Part / No: 05 ? 

thanks in advance

Apostolos