How do you edit your comment that you make to someone’s an inbox reply? I couldn’t figure out how and ultimately had to visit my own profile to edit my comment from there.
There isn't a single way to do it but I can explain how I do this fast. Btw I assume you mean you are replaying from the message screen. After I hit reply, I will hit the "Go to context" icon button (it's the icon on the right that's part of the "Context" box). This will open the post (the app should auto focus on the comment you just sent if not you will need to find your comment). Then I expand the comment's actions by tapping the body of the comment (you can also tap the left side of the comment or long tap the comment by default). Tap the three dots button for that comment > Edit comment.
How do you search for a certain post title in just one community, such as /c/summit?
Tap Search (bottom nav bar) > Tap search field > Type your title query > Tap "Filter by community" > Search for your community > tap the community from the results > Tap the search button.