If you can use amule in a lecture, you are a very happy guy. All institutes I know have proxys that allow only port http and https traffic. Sometimes pop and smtp, but they don't nat anything.
And if you have a notebook, you don't have to shutdown. These things are designed to run from Accu, so you can carry it to the lecture or mensa or toilette without shutting down the whole thing. Maybe you have to use cabled mediums, but when my ISP disconnects after 24 hours, the sources come back much faster than starting amule, so I don't see any need of this "feature".
Btw. a timestamp has usually saved data and time like 200510091106 for now, and that is much more than 4 byte, it is 12 Byte. And a source has usually save IP and port of the source, either with dots 84.171.66.85:4662 which has 17 Byte, or with 0's like 0841710660854662 which has 16 Byte. Both are much more than you say. Sure you could zip them, but I don't think that that saves much.
In both case I come for 100 source to 1712 Byte, or 1812 Byte. For 200 downloads that is 342400 Byte (334,375 KB) and 362400Bbyte (353,90625 KB). My Temp-folder is mounted over a samba share on a 100MBit/s LAN, that would mean I have to wait 2,7 or 3,4 seconds longer for a shutdown. And I didn't calculate the Ethernet Overhead.