So I managed to flash back to 3.32 and VI 4.0 after 2 days of mercyless bootlopping.
What I did was :
1- superwipe everything, flash latest TripOS rom
2 - reboot to bootloader and flash Trip's latest firmware (this way, I knew I woul have both a matching rom and matching firmware, avoiding incompatibility issue). Trip's firmware rewrites a huge amount of things, and that seems to put an end to what was causing my bootloops.
3 - reboot and let the phone alone for 10 minutes, just to let everything settle right.
4 - reboot to recovery
5 - Superwipe again
6 - flash my rom (in my case, VI 4.0)
7 - power off, and boot to bootloader
8 - flash 3.32 firmware
9 - reboot and let the phone still for 10 minutes
So far everything runs perfectly (I just have a splash screen saying "Trip'n Nice" on it) and it saved me from going into the process of flashing a RUU, rooting the RUU, installing recovery and so on. Give it a try, it might work for you to.
Just some art from my little hands :