I am very excited to play STO, MMOs have always been a part of life for me, moving from one to another as new ones come out. What has really made it more enjoyable for me is being able to share this with my girlfriend over the years. However, she is not what most of us would consider a "gamer". In most MMO's she does good, but not great. The primary reason she plays is to "be with me" through the whole experience.
So obviously i would love it if she joined STO, but I cannot answer her question of how grouping really works in this one. So i come to you, the community for the answer. After the initial "training prologue", is it possible to be grouped in space and on the ground for each and every mission that comes our way? Or is the mission setup made so that its mostly solo-play until and only until a large group mission comes along?
You can go in both directions. In CB and OB, I experienced that a good portion of the starting quests (Sirius sector block) were easily solo-able. As you get further on, you'll notice that the constant extra person(s) can help speed things along greatly. Forming a group and joining the same instance of an area will keep you and your group mates together, so answering your question: Yes. I don't see why you can't party for everything. Leaving instances doesn't clear your group, and you can swap instances to be in the same one at anytime from the map screen (i believe it was added on map screen in OB/late CB).
I find things most fun with a team of two (assuming your partner is someone you know and can coordinate with).
Group play works differently in Space and Ground.
In Space, the number of enemies will increase based on how many players you have. So as a solo player, you will find yourself fighting either one strong enemy ship, or three weak enemy ships, in each fight. With a full group of Five players, you will find yourself up against a small fleet of enemy ships, in every battle.
Ground works differently. The enemies do not scale with your group size. In solo ground combat, you have four of your bridge officers with you, helping you fight. But as you add players to your team, they take the place of bridge officers. With a team of two, one captain will bring two if their officers, and the second captain will bring one of their officers. With a full group of five players, everyone is a player, and there are no bridge officers. Either way, ground play is your team of five, versus whatever enemies are in the area.