The road extending from Charles River avenue to Paul Revere Park should be called Warren Avenue per streetlevel imagery and the Massachusetts Interactive Property Map.

https://massgis.maps.arcgis.com/apps/OnePane/basicviewer/index.html?appid=47689963e7bb4007961676ad9fc56ae9

D.L. Moody Historic Marker

onosm.org submitted note from a business:
name: Patriot Care Corp
phone: (617) 500-1375
website: https://patriotcare.org/
twitter:
facebook:
email:
hours: Mon-Fri 10am-6pm, Sat-Sun 11am-3pm
category:
address: 21 Milk Street Boston, MA 02109

Unable to answer "What’s the house number of this building?" – Train Station Building – way/737897576 via StreetComplete 57.4:

I very much doubt that a subway entrance (even if used to put some stairs to sit on on top) has a house number. At least I couldn't find one.

onosm.org submitted note from a business:
Name: A1 Auto Transport Boston
addr:street=175 Portland St #10
addr:city=Boston
addr:postcode=02114
Phone number: 6172865909
Website: https://www.a1autotransport.com/boston/
Opening Hours: Open 24 hours
Category: Transportation
Description: A-1 Auto Transport is one of the largest nationwide auto shippers in the industry. We have offices and storage facilities located in major cities and metro areas throughout the U.S. and overseas, as well as a staff of experienced shipping professionals to make sure your shipment arrives on time and at the right price. As one of the largest US-based worldwide auto shippers, we know how to navigate the process, making it as easy as possible for you. It's about more than just shipping for us--we're dedicated to providing you with all the information you need, getting you the best possible price, and leaving a positive impact on our communities by delivering freight on time every time.
Accepted payment methods:
takeaway=yes

Unable to answer "Is this place wheelchair accessible?" – on level 0: Kenmore (Subway Entrance) – node/7776200202 via StreetComplete 58.2:

Theres an elevator to the right of this entrance (its the detached blob on the map)

Attached photo(s):
https://westnordost.de/p/233677.jpg