I'm not 100% sure how the init.d system works on other AOSP roms, but on Cyanogenmod, you can place this script in the /data/local/userinit.d directory (creating the userinit.d directory if necessary).
#!/system/bin/sh
chmod 666 /dev/ttyHSL1
setprop persist.sys.lge.eula_agreement true
adb root
adb shell "mkdir -p /data/local/userinit.d"
adb push 10QuickRemote /data/local/userinit.d
adb shell "chmod 755 /data/local/userinit.d/10QuickRemote
adb shell
--- inside adb, as root:
# sh /data/local/userinit.d/10QuickRemote
# ls -l /dev/ttyHSL1
-- result should be:
crw-rw-rw- system system 245, 1 2013-11-06 08:20 ttyHSL1
# getprop persist.sys.lge.eula_agreement
-- result should be:
true
-- inside a root shell
# chmod 755 /data/local/userinit.d/10QuickRemote
i guess carbon has no userinit.d support.
you could try to move the 10QuickRemote userscript from "/data/local/userinit.d/" to "/system/etc/init.d/" with any root explorer.
only downside to this method is the script gets removed after flashing a new rom