Importance of waiting for the last person to finish before leaving: Berachot 5b-6a
Waiting for others to finish (see above) in modern times: Tos. Berachot 6a #1
The time when the Congregation prays is considered to be a time of Hashem's Accessibility: Berachot 7b-8a
Praying behind a Synagogue: Berachot 6b
The Manifestation of Hashem's Presence stays with a quorum which is praying: Berachot 6a
Distinction between the Blessings on Recitation of Shema of individuals and of a Congregation: Tos. Berachot 13a #1
Ability of each Jew to pray individually: Yoma 52a
It's inappropriate for an individual to be uninvolved while everyone is praying: Berachot 20b-21a
What to do if one enters the synagogue while the community is praying, but one has already prayed: Berachot 21a-b
What to do if one enters the synagogue while the community is praying, and one has not yet prayed: Berachot 21b
Avoiding disturbing others during prayer, by praying loudly: Berachot 24b
Acceptance of insincere prayer when one prays alone, vs. when one prays in a community: Taanit 8a