Thanks a lot for your comment (and for taking the time to appreciate the project's page also, I did the illustrations in the last few hours of the jam while listening to my tracks in the background to not lose time on reviewing and adjusting the mix, it was quite intense) !
It was quite an adventure to mix all the synths, drums and guitars (especially on the 3rd track with all the different layers on top of each other), so I'm glad that you enjoyed it !
And for the last track, I used the Archetype Petrucci plugin by Neural DSP , using a clean sound with a lot of reverb/delay
(the plugins have free trials and they might be on sale for 50% off around Easter so I really recommend trying them for heavy and clean sounds). I think I used a Jazz III pick (like most of my guitar playing) to get a bright and clear attack for the track, and think I kept my guitar switch on normal mode (not Treble or Rhythm) not to get an overly light tone.
Anyway thanks a lot for listening and for your feedback, it is always appreciated !