Welded shut heater pipes

[heated heavy]

I noticed the other day that the shop that did my SR20DE swap completely welded shut my heater pipes leading to the firewall instead of looping them together to allow water to circulate.
Would this effect my coolant temp sensor or AAC valve (since it is connected to one of the pipes) in any way at all.
My car is running rich, idles bad, and even dies occasionally at dead stops.
Ive recently insalled an adjustable FPR, new O2 sensor, checked timing, checked injectors for leaks, checked vacuum lines for leaks, and checked AAC valve.
I also noticed when I checked my AAC valve that my intake ports in the head had a puddle of dried up fuel. I dont know if was from before I installed my adjustable FPR or if it is still being flooded with fuel.
I also have to crank my engine about 10 times to get it to start. And when it does it stutters and wants to die unless I give it some gas so it can idle without dying.