Romans 14:19 - So then let us pursue what makes for peace and for mutual upbuilding.
[Those who have read my Saving Righteousness book will now how much I love that verse]
Romans 15:7 - Therefore welcome one another as Christ has welcomed you, for the glory of God.
I think these two verses some up much of the exhortation in 14.1-15.7 and I wish all churches had them written somewhere in the auditorium or etched on the desk of all committee meetings.
Trying to teach about the "weak" and "strong" is a bit daunting also, both at a scholarly and popular level. Were the weak Jews, Jewish Christians or Gentiles?
Horace (Sat. 1.9.68-72) includes a story where one person refuses to speak to another person and the approached person says:
The other replies, "I have no scruples".
Then he retorts, "But I have. I am a somewhat weaker brother, one of the many. I will talk another day."
(See commentaries by Ben Witherington and Charles Talbert).