is there any sure way to know that i even have a network connection?

If you get your IP from a DHCP server, you can see with ifconfig that you did not get an IP number.Get ifconfig from a Debian image.

somewhere in /proc maybe? so i can make the script conditional.

you can see in /proc/empeg_power whether you're on AC power or on car power.

even though the database and playlist is functional, everytime i run emplode after rsync is done, it has to add/change something

I noticed that too. I think it's because of some timestamp, not because of something in the database. I tested this in an earlier mp3tofid version; the databases created by emplode and by mp3tofid were 100% identical. With current versions they are not, because mp3tofid is leaving some tags out of the database that do not have to be there. This makes the database, and thus the player's memory usage, significantly smaller.

Pim