As the other posts say, timing belt is either perfectly ok or your engine is ruined. There is no intermediate condition. If no proof exists it was changed on schedule in the past, change it or have it changed immediately.

The valve on the fuel rail is for bleeding off the fuel pressure so you can safely work on the fuel system. Also allows you to measure the fuel pressure with an appropriate gauge.

It is unusual to have so many codes at one time. It suggests a generic electrical failure. I would reset all the codes and wait to see if they reappear, but before you do FIRST do these things:

1) Check that the charging system and battery are maintaining proper voltage and have no loose or corroded connections, including earth points (grounds). Do not remove any connections in the system while the car is running or ignition is on.

2) Inspect all the wiring harnesses for breaks, corrosion from water and/or salt spray getting in, heat damage, excessive flexing, etc.

3) Was your car in a major accident or had the instrument panel off, for instance for a new A/C evaporator? Or the transmission off for work or replacing main seal? If so then whoever did the work may not have reinstalled wiring or connectors to dashboard, console, or gearbox securely and something may have shaken loose.

4) Do all of the electrical accessories on your car work? If some don't, this may also point to where damaged or broken wiring might exist.

5) Don't hit sensors with a hammer or tool. They are definitely breakable.

6) Maybe the stalling is due to a fuel system problem (like dirt in tank or clogged filter) not related to all the codes?

All of the above are events I have experienced on various cars I have owned.

Good luck, and relax!!