Thanks a ton again for all the continued support and advice! I've just spent another couple hours sorting through things and playing tetris and I've now managed to reduce the load significantly. As it stands I've got:
1x Pannier bag (full) with clothes, sleeping gear & bike repair stuff. Weight: 5kg
1x Pannier bag (half full) with electronics, toiletries, stove. Weight: 5kg
Then I'm only left with my tent (2kg) plus my emergency 2x3 meter tarp (0.5kg) that I'll tie on to my rack. I'm considering dropping the tarp as well, but I can see it possibly being useful (a) in case my tent isn't fully waterproof (b) I'm making camp on bumpy ground (c) I want to conceal my tent better. If I don't end up using it I can easily give it away, thing only cost me 5 bucks.
Now I'm wondering: I'm planning to take the half-full pannier bag with me when going shopping, because (a) this bag contains my most valuable items and (b) it's where I've left room for food to go in. As it is the bags both weigh exactly 5kg, but if I throw 1-2kg of food into the half-full bag, I'll be slightly off balance (5kg left vs. 6-7kg right). Is this something to worry about or not noticable?