And there is no need for a science officer when Data seemed to fill the role just fine.
So your whole point is that she shouldn't be part of the bridge crew? How does she evaluate crew performances then? And the fact that she'd only behind Captain and XO in importance when it comes to alien life forms (which is the primary mission of the ship) means nothing?
Again, you seem to think that the role is that of a therapist, but it's much more than that. She is an officer as well and a alien expert and acts in an advisory role.
Your way of thinking is wrapped around a 20th century "shrink" and it's not the same at all.
On these points: This is true of Troi as she was originally envisioned, perhaps, and certainly of how she was in the show in the last couple seasons. But the fact is, that's not how she came off during seaons 1-5 for the most part. She
acted like she really was first and foremost a therapist. More often than not, unless it was a Troi-centric episode, her presence on the bridge (and she was almost always there) didn't amount to much. Add to that the idea that she was supposedly a full officer, yet wore that ridiculous outfit instead of a uniform (the one really great thing Jelico did for the Enterprise was rectifying that mistake!

), and in "Disaster", she
didn't know what a containment breach was. The idea that any officer or crewman wouldn't know that is absurd. So while it made sense in theory, the reality of the show was a little dodgy.
As for Data, he was certainly quite capable as a scientist, but the idea that there was no "Science Officer" is pretty unrealistic with respect to established Starfleet crew structure. Data was the Chief of Operations, which is a department of it's own. So is Science.
Someone has to be the department head for all the blue-uniformed extras you see at the bridge science stations (among other places). The reason we didn't see a Chief Science Officer (and that Data basically filled that role) is because it's a TV show. No one had been cast in that role, so it was absent.
You'd think that Starfleet would realize that having children on board starships was a bad idea after the, oh I don't know, first 40 or so disasters involving starships. Hell, you'd think Picard would have realized that after the children were KIDNAPPED by aliens.
For a ship that was repeatedly put in potential combat situations (BOBW, Redemption, Chain of Command, Generations, etc), doesn't having children on board make no sense whatsoever? What do they do, make a detour to the nearest starbase to dump off the kiddies whenever it looks like things are getting dangerous? At least they got rid of the kids for the Ent-E.
Agreed. Ronald D. Moore once said he thought of the whole families/children on the ship as exactly what I think of it as: an (ultimately failed) experiment. He put it best when he said that "There was always something awkward about Picard ordering the ship into battle situations with kiddies running through the corridors. And no matter how much lip service we paid to the "our families are part of our strength" concept, it never seemed very smart or very logical to bring the spouse and kids along when you're facing down the Borg, or guarding the Neutral Zone, or plunging the ship into uncharted spatial anomalies."
I think there was some merit to it when the Federation went through a relatively peaceful time (pre- and early TNG), but it's an unsound concept in the universe of Trek anytime post TNG season 4. Continuing on this topic...
Only if you think children are more valuable as adults, or their survival more important than that of grown-ups. Which may not be true of the brave new world of the 24th century any more.

I find that to be a rather... odd, viewpoint. And one that there is zero evidence for on the show.
It made sense for soldiers up until very recently: what was the point of having a family if one would never see it? Back then, the inability to see the family while on leave was due to the inability to traverse the vast overland or overseas distances from one's assignment to one's home. Today, that's no longer an issue - but it will be an issue again if our troops get aboard starships that stay away for years at an end.
Tough. If you want to be the type of father/mother who is really around for their kids, then don't join Starfleet. Or, take one of the many thousands upon thousands of postings that are either on one of the huge starbases (keep your kids with you), planetside (keep your kids with you), or on a ship that has a static assignment in a core sector (always within several hours travel time of whichever Fed planet, where your kids live). If you accept an assignment to a ship on deep-space exploration duty, or patrol duties along hostile borders... you can't keep your kids with you. Make the choice.
My take on it (which will be applied to the Trek stories that I am always working on) was that it was something that was scaled back heavily as the reality of just how dangerous shipboard life in the late 24th century was became more apparent. However, on certain ships, bringing a spouse/significant other on board would be allowed under certain conditions. Specifically, I envisioned that the civilian in question would be given a battery of tests (psychological, mostly) to determine if they can really handle the realities of life (and the potential for sudden death) aboard a Starfleet vessel. Only in those cases where the person passed the test (and signed all the "I understand that I'm putting myself in extreme danger, and my family won't hold Starfleet or the Federation responsible if I die" wavers) would they be allowed to live on the ship. And some ships wouldn't allow this at all (though peacetime Galaxy-class ships, with their deep-space exploration assignments, likely would allow for this).
And children would never be allowed. You want to have kids, again, you make the choice: see them only when you can get shoreleave, or arrange for a different assignment.
Referring to families on the E-E:
Don't be so sure. They could well still be there even if we don't see them.
I highly doubt that. I will grant that I don't have any more direct evidence against there being families on board than you have direct evidence
for it. That's just my gut feeling.