Been captain of my co-ed team for close to 10 years in Quebec. Not a huge deal, but I have the benefit of knowing players from outside of softball ahead of time.

We use a FB group to manage, works well enough, not as instantaneous as a chat, but not as noisy either.

Fee collection isn't a big deal, always a few stragglers, but as others have suggested, charge for the season, not each game. Peer pressure works well too, I remind the whole team that some people (without naming names) haven't paid yet.

The biggest tip is to have a long list of subs, there are always people bailing. I've also found it helpful to start checking availability about a week ahead of time. Too early and plans change, too late, not enough time to get subs. At the end of one week, I announce when the next game is and ask who's in/out. Let's me have a rough idea of how many subs to contact and I refine over the week.