I'm in the early stages of removing my kitchen soffit and have run into two problems I could use your expertise in addressing:

Sink/Dishwasher Vent Stack

The sink/dishwasher vent stack runs up an exterior wall and makes a few 90 degree turns to work around the top plate, cutting through the soffit to run across the kitchen ceiling.

Would it be ok to reduce this to 1.5inch on the vertical stack, notch into the double top plate, and extend the horizontal pipe to meet in the joist bay?

There is a single electric run currently behind the 90 degree connectors that runs to our sink light. I am comfortable rerouting this through the joists after correcting the vent stack.

EMT Below Joists

On the other side of the kitchen, I have a EMT that enters from above the existing ceiling line into the soffit and below a joist in the soffit, then taking a 90 degree turn out and above the existing ceiling.

The EMT has a connector located right below the joist. I can see that the EMT is bent to allow this set up and is not pressured under the joist.

Once I have the soffit fully removed, would I be able to notch the joist it crosses under and bend the EMT without disturbing the existing wiring? Any other solutions I'm not thinking of?

Photos

https://imgur.com/a/wp3u7zS

Thank you!