So its not new then. A lot of its state will be down to its previous owners, how they've driven it and how they've looked after it, or not. Very unfair to blame Fiat for it all.
Engine failure warnings: Have you diagnosed and attempted a fix? If not, then it will keep lighting the warning until the problem is fixed. Needs
MES diagnostic scan to read the codes.
Airbag warning: Possibly the only genuine Fiat blameworthy issue. Stilos do seem to eat their airbag modules, hiding in the centre console, under the heater. Need to replace like with like, a search on Ebay will usually find a replacement.
Handbrake: If it is trying to rise, the cable has too much slack, which could indicate seized adjusters. Maintenance!
ABS: If jolts cause any electrical issues, look for poor connections. Again,
MES should highlight which wheel to start at.
Cutting out: Poor connections, possibly at ECU. OR, might start with the main battery cables, they are known to corrode internally, especially Pandas and Puntos, so no reason that Stilos should be immune. Might even be the cause of all the electrical maladies.
So, please, look at each issue methodically, and fix them, then enjoy the car. If you need help, then explain what you've found, best in a new thread, and help will arrive.