I didn't see any ground-breaking advice in the article. Yes, it's good to get input from everyone before the trip. It's important to include something for everyone; not necessarily everything for everyone - and certainly not everything for only one person (even if it's you). Yes, it's important to keep a sense of humor and keep it fun. Yes, it's important to agree on your pace of travel. Alone/down time is a personal thing. Some people need it, others don't. I'd prefer to have a plan that includes options, rather than a set list of to-dos. If someone doesn't want to go to another church on a given day, it should be fine for them to beg off while others go. If everyone is burnt out on churches, do something else. It's a life-saver to have a list of alternate sights or activities (pre-researched) on hand.
It's important to agree on accommodations. I recently traveled with my girlfriend in Ireland. I was there for 17 days, she was there for 7. During my alone time, I was happy in hostels. When we were traveling together, however, we had discussed what she "needed". A private room and private (not necessarily en suite) bath were her minimums, so we did a lot of B&B's that promised a private bathroom.
Same for food. Know what people will or won't eat before you're on the road as well as agreeing on preferences for dining vs. getting something on the go. My girlfriend likes to sit down and eat a meal slowly - figure around an hour, or more, per meal. That goes against my natural inclination to grab something and eat it on the go. I was willing to eat on her schedule, knowing that meant less time for sights. I knew that going in, it wasn't a surprise when we were traveling. It didn't become a source of controversy.