Mass Effect 3: Why all the trouble?

I love this game to death but I still have many questions and things that annoyed me about this game, that for many other people, wouldn't even care about.
First of all, during the battle for the Citadel they made a big deal about saving the Destiny Asention, however not once did I see it fire its weapons, even at the very end of ME3 I saw it sitting there by the Citadel and it wasn't doing a damn thing.

Second of all, I really wanted to see Shepard have a kid or some kind of family started with the love interest of your choice, there was a 2 month period between ME and ME2, during that time frame all they were doing was looking for the Geth who I might add were inactive at the time. Speaking of love interests, why do they show Liara T'Soni completely naked but not Female Shepard? same body parts, just a different skill color.

Another thing, If you pick the correct ending and you see the destroyed buildings of London again, does anyone actually find Shepard laying there? or does she just die laying there in the debris.

Last of all for now, if you get the right war assets like the Drell, Elcor, Hannar, Salarians, and the Batarians, why are they not mentioned when Joker is telling Shepard which fleets are reported in? It seems a bit odd that you go through the trouble for finding them but then they don't actually count in the fleet total. I know the Salarian STG and the Krogan are there, so are the Turians and Asari but I've never seen a Batarian, a geth, a Quarian or an Elcor fighting on the ground for the final fight, which I might add was a bit disappointing for taking back an entire planet. I was hoping to see an all out engagment through out more cities then just London, what ever happened to Vancover, and New York? Also what happened to all the nuclear weapon deposits that The Americans and Russians had during our time? Could of taken out a few dozen reapers with them and saved many more lives.