Is the concern here that the stringer does not butt up perpendicularly to the floor framing?

So the question here is, what is the frame above the wall... if it runs parallel the wall is likely non-bearing, if perpendicular it is likely that it is bearing. 

So the question here is, what is the frame above the wall... if it runs parallel the wall is likely non-bearing, if perpendicular it is likely that it is bearing.

They run perpendicular to the homes and branch to each lot. 

Here are a few suggestions that would apply to one or the other...or both:1 - WIC doors should be away from the perpendicular wall of its bedroom.  

Load bearing walls will be perpendicular to these.

You still run across places in my area, as you must also in Scranton, where the original floors are face nailed heartwood pine boards (of varying thickness, usually 3/4 in) over 1-inch perpendicular plank subfloors spanning the floor joists.

Is it possible to move the kitchen peninsula so that it is perpendicular to the wall that now has the pantry/storage? 

The floor beams in the attic were not modified to support it as living space, the walls coming off the roof did not have the 2x4s placed perpendicular for proper support so they were flimsy.

Well, you can always throw money at things when you hear about unexpected issues, however; the problem is where this storm water pipe needs to go, there is a sewer pipe directly perpendicular!