i have an issue i need help with. coolant related

[Sablea4]

so, for a while i have been having problems with my car. ill explain what happened in some detail..

1st...i am leaking coolant from here. its a slow leak but it is constant. i have to refill the reservoir every now and then. is there an o-ring or something or do i need a new pipe?



2nd...it has not done it in a while but i have had the car turn its self off and didnt want to start back up after about 30-45 minutes of medium to hard driving. this happened a couple of times on the trip home as well. all on the same day. it almost felt like i had blown off an intercooler hose because every time i got on the throttle it would hesitate and try to stall out. and not one single check engine light the whole time.
....after this i did an oil change and changed the plugs and have not had a problem like that since.

3rd...it also seems that the coolant system might have a bubble of air in it but i dont know for sure.

it has been running fine but i just want to find out whats up before i drive to NJ for waterfest.

so...any ideas? maybe my thermostat? do i need to flush the system? any help would be appreciated.

[F16HTON]

That is the bleeder valve and it is a very easy DIY repair the OEM part number is WHT 000 316 and you get a new plug and seal.

Cost at the dealership is about $2.50

Should be covered under warranty.

[Sablea4]

is that causing all my problems?