Thanks for the replies, everyone. Spent a bit of time thinking over this stuff.

1. That hotbar of chat macros I'm thinking about is going to include some greetings at the start of the Duty, and I'll be using them just before I use start up buffs.
2. Admittedly, I was recovering from a nasty set of runs, so I got a little too harsh on speedrunners, there. I'm not going to put the burden of opening communications entirely on them, and I'm going to try to set an example by consistently using my greeting macros, including one asking if everyone can handle a speedrun, since I've done my own share of Allagan Tomestone runs.
3. Additional macro I'm going to make: Ready check.
4. I'm going to use the Party Finder more often, now that I'm getting familiar with it.
5. Not sure what specific method would be most appropriate, but I'm thinking of doing interviews with people who main other classes so I can get more on their perspective. Had a little daydream where I was doing a guide series called "Getting to know your [class] friends," that was essentially about how to work with people of a certain class, rather than how to play the class itself.

I'm going to spend a bit of time tonight fiddling with my HUD to see how much I can reasonably fit on there. No point in writing chat macros if I cover my entire screen with them, after all.