ocr , votings disk question

1, ocrconfig can back  ocr, but they seem must run root,

why ocr disk permission must  be root:oinstall, can it be oracle:oinstall?

ls -ltr /dev/r11g_ocr1
crw-r-----   1 root     oinstall     46,  4 Nov 17 14:11 /dev/r11g_ocr1

2.why voting disk should  oracle:oinstall, can it be root:oinstall?

ls -ltr /dev/r11g_vote1
crw-r-----   1 oracle   oinstall     46,  1 Nov 17 17:57 /dev/r11g_vote1

3.view ocr configuration

/oracle/crs/bin/oifcfg getif
bond1  10.69.18.0  global  public                             --vip suvnet  what user
bond0  192.168.1.0  global  cluster_interconnect              --pri subnet  waht use

what is public network mean ？ what is   cluster_interconnect  network mean?

if all two not set, can crs start successful?