I get venting. Vent away. That said, I do think that you are reading too much into and worrying about things that aren't necessary.
I don't think your parents are being controlling. I think they want to spend some time with their entire family and because that's what they want, they are generously paying for everything. That's a good thing.
Anytime you have any sort of plans with multiple families, you are going to have different wants and different opinions. You can't make everyone happy and so you compromise. Because your parents are paying, the final decisions are their to make. That's the way it works. If you were paying for everything, you'd have more of a say-so.
As far as the comments about your teen. I think you're taking them to personally. All of the other children on the trip are under ten so that's where their focus is in finding a resort with activities. Under ten is the age group majority. They aren't intentionally leaving out your DD, they're being logical.
And to be honest, any inclusive resort that has activities for younger kids is also going to offer activities for teens as well as special activities for adults. You are worrying for nothing. Activities aside, as long as there is a pool, a room, food and other people to interact with, a teen (anyone for that matter) is perfectly capable of having a great vacation.
As far as softball goes, they've given you a date to work with a year in advance. You already see the coach. Go talk to him. Now. You could speak with him right now and either get the okay or find out you need another week. You aren't. The one holding back here is you, not your parents. Why? Because of what he might think? He might be impressed by what a planner you are and appreciate you're thinking so far in advance. Who cares what he thinks about you approaching him now.
Finally with the flights.....your parents have essentially said "don't worry about the flights, we've got someone making arrangements, we're paying for tickets, all you have to do is relax and show up". And you're (and other posters) are finding all these things that you should be worried about when you don't have to be. That's your control issue.
There is a free trip in your future with the potential to make some great family memories. You can 1) relax, go with the flow and have a fantastic time or 2) read into things, worry and look for things to go wrong that haven't even happened yet.
The trip is what you and your attitude make it. It's a year away and you're making it out to be a headache. Why not think positive instead and make it a great trip.