I doubt that syslog gets the chance to even start. Kicking watchdog should start immediately when control reaches Debian (the first thing to be executed by its init script).

It depends on your init system. If using systemd, it should be the first service to be started. If using SysV init, you can put it on top of main init script to be started in the background.

Kicking watchdog can be achieved using a simple infinite while loop with an echo command to a special device file. I don't remember the device file now but others can help if you don't know it already. It is done in ubiboot too, or you can find it in Harmatten/Nemo/SFOS/Nitroid init scripts for N9.