Would he want to do so?
What would he do?

Sherlockismyfix wrote:

I think he doesn't respond to her texts for the same reason he takes her pulse.  The scientist in him is collecting data.  You don't muck up a research study by introducing additional variables, which a response from him would do.

Having said that, he can see that she is very clever and this clearly fascinates him. We have seen over and over how Sherlock makes missteps when confronted with brilliant opponents who appeal to his vanity.  Irene knows this and is smart enough to use it against him. Irene plays him like a fish for most of the episode by 1) appealing to his vanity by challenging and admiring his intelligence, and 2) by casting herself as being in need of protection and coming to him as a 'client'.  This is where we see Sherlock at his weakest. It is only when she mentions Moriarty at the end that he is able to grasp the big picture, and with that final piece of the puzzle, he is able to very rapidly figure out the rest.

Whether, throughout all of this, Sherlock was engaged on a level beyond vanity and intellectual inquiry?  Well, that has not been made clear.  My head canon says that if Mrs. H. hadn't turned up, he would have allowed matters to go further...  and that much later, when he sees her again in Karachi, they indeed have a fling - as supported by comments Benedict himself made in an interview.

(Don't shoot me, I know there are many different views on this - and I don't ship the pair of them.  She would be a terrible partner for him - they are too similar. I do think he could do worse than Molly, however.  He seems to enjoy his 'goldfish'.)

I can't agree with you more on the science part. I don't think he would throw away all the clues before he solved the puzzle.
For him I think Irene was a puzzle, maybe of love or something else. The main point is he couldn't solve it in the first. And this is also the reason why he didn't reply. He is someone who would never reply until he see through the case. Mostly he coul

Childsplay wrote:

the
creator 
of
this 
summary
is
superlative

-ChildsPlay

But how?

I don't think they would do that, either. But I think it's a little arbitrary to say no love existing between them.
There are too many kinds of people, especially Sherlock-Irene type, they would never express themselves in normal way.
But of course I don't mean that they're definitely in love with each other. There's still a possibility, here.

I would like to believe that they are talented in different areas. They're both good at deduction, but Mycroft is more skilled in analysesing systems, and Sherlock criminal.
In the original books, Mycroft is someone who helped the government to work more effectively.

In this situation, I think, "let down" means, he would always be a lunatic, never reply them directly, or would never communicate with them in a normal way.
Don't expect Sherlock being nice.

The reason why Sherlock said that Mary saved his life, I think, is because Sherlock is a reasonable man, everything he think and do is almost based on logic. And when he met Mary in the Magnusson's office, the only reasonable solution to Mary for him was to kill him. But instead, she chose not to. So Mary saved his life.
As to Mary's sacredness, presumably if you were Mary, would you felt a scary when someone knows your deep secret is just wake up. When she pulled a bullet in Sherlock's body, every normal person in her position would hope the best result is Sherlock would be in a coma forever. Would anyone agree with me?
So I would say, when she heard about Sherlock'wake-up, she would feel both happy and scared, only scary is much more.

Maybe this is a selfish opinion, I would like to see Sherlock keep his loneliness.
The reason why I hold this opinion is that as far as I can see, someone with a great talent like Sherlock their god-send gift has always isolated them from others normal people. This is both a gift and a curse. They have to be lonely to keep their talent, their specialty. Happiness always ruin them.
Happiness or "OMG", that's a question.

There's a Chinese video on-line website company called youku. They got the copyright from BBC, and of course it's because it could bring them a huge attention from the Sherlock fans.
And it kinda surprised me that you don't know there is a lot of Sherlock fans in China P.R. And we also have our forums of Sherlock.
I think the only difference between our forums is just we speak in different languages. But all share a great love to Sherlock.
And many only to understand the series by the translated titles, even this couldn't stop their love to Sherlock.

I am dexter from China, a huge Sherlock fan, thanks to the internet, we can talk about Sherlock in the same place. And who knows, may we meet Sherlock here.
Thx