Update:

I bought a new battery and immediately got some improvement regarding the flickering lights and such. However, it won't start without the relay I posted a pic of earlier, and when I tried to reinstall the old one nothing happened so I guess and hope that this is faulty 'cause I have two new ones coming my way tomorrow...

Anyways, the relay, or starter relay might be a better word for it, seems really poorly described in my Haynes. I cannot find it in the wire diagram either... Any clues to this? I cannot for my life understand the colors of the wiring in the relay compared to how it is supposed to look in the diagram but I mean, the bike used to work, right?

 

Short update:

After having replaced the entire electrical system (at least that's what it feels like, having replaced the battery, the main relay, the R/R, the starter relay, the fuses etc.) I managed to get the starter motor going when I press the button. Good. It still won't fire up properly. I almost got it running while push starting it, but it wouldn't really fire up but rather cough a couple of times before dying no matter how much or little gas I gave. Hopefully it's just the new battery that is a tad weak, I have charged it overnight so it might work today, otherwise I'm pretty clueless. Checked all the fuel lines, the airlines and such, nothing weird. Everything looks grounded to me as well... Anyways, I'll write a more thorough update tonight when I've been tinkering a bit more with it.

 

Good luck.

Post a video of it trying to start, might help others diagnose your problem.

 

Last update (I hope): It started and it ran. Sure, I have apparently managed to do something to the front brake light switch but still: She runs! Pretty great too... I guess all it needed after having received so many new parts was a fully charged battery...