Tinkling chain is normally the top chain. Have you checked the guaze filter under the banjo bolt on the timing chain oil feed. Could also be stuck top chain tensioner or broken top chain guide. Chain can make this noise on start up but stops after a few seconds when oil pressure builds.
That’s for a v8. Don’t need to do that on a 4 pot. You’ve got an air lock. Run engine until stat opens with rad cap off.keep revs at around 1500 rpm topping up coolant to just under rad filler. Put cap on. Let off revs. They normally push a drop out at first when you use car but will find its...
If it has changed the braking I would still suspect it. Might be worth taking it apart and checking the diaphragm. The light could be a sodden cork float in reservoir cap, a duff handbrake light switch or a short somewhere.
Right it’s the air admittance valve. The white flying saucer looking thing prize off small cap catching spring as it pops out. Wd40 on plastic sliding bit make sure it slides in and out. Stretch spring a bit put it back and try brakes.