As much fun as I've had playing, I still have to say that the AI for this game is neither good nor well thought out, especially when it comes to diplomacy.  But you do have a couple of misconceptions in your post.

Alliances require close relations, the next step after friendly.

Race attitudes are what each individual race feels about the other, not a combined relationship ranking.  It's easy for a race to like another race that hates them, just as one person can like another person who doesn't like them.

Don't be so free with your techs unless you get something in return, because the AI races will not return the favor.  Ever.

You're best off if you consider every game to be you against every other race, because that's the way it's going to be.  You have to pay for help from them, and their attitudes towards you, and each other, changes constantly.  That holds true even in campaigns where races are supposed to be on the same team as you.  The AI isn't designed well enough to understand the concept of ally or teammate. 

Others will disagree with me on this, but I've found it much easier to deal with evil races than with good or neutral ones.  The evil ones are not only more predictable, but they usually have low diplomacy skills so you can get more out of them at lower costs.  But again, remember that you're on your own.  The AI races are not your friends.  The only things alliances are good for is an alliance victory and getting you into wars you don't want to fight.

I mostly agree with you, but better doesn't mean good, and it does have some gaping holes in it.  Look at these boards to see loads of complaints about AI logic (or lack of logic), and even more posts about how to exploit AI coding weaknesses for fun and profit.  So far, I haven't seen any strategy games of this type with a really well coded AI.

I generally do not trade techs with the other major races, and try very hard not to do so unless I have a huge diplomacy advantage.  The closest thing to exceptions are:

1) To get them to declare war against another AI, or

2) I really need that specific tech (e.g., I've been researching beam defense and suddenly need armor), or

3) The tech I get in return gives an empire-wide bonus (e.g., banks gives a 5% economic bonus even if you never build one).

The tech trade I like the best is to trade Trade to minors for something I want.  Not only do I get something, but the Minors soon set up trade with me for new cash flow and more cash for them to give me in future trades.

Actually, I can and do, especially since some of the things that the AI does, or doesn't do, aren't that hard to change. 

TBS games are a small niche market these days, and I think the AI coding is the reason for that.  If you want to see good examples of coding laziness, play the campaigns (if you haven't already).  There are many scenarios in them where you start with fewer researched techs than you started with in the previous ones.  In some you see a story line telling you that one race is fighting for it's survival against another race that launched an all out attack on their home world, yet neither one knows how to bolt a weapon onto a ship hull. They have no attack ability at all, and their fleets consist of one or two scout type ships.  Sloppy design. 

But I didn't come here to bash the devs or hijack the thread, only to let the OP know what was going on with his game since nobody else had replied to him. 

If you'd care to keep the debate going in another thread, I'd probably join in on the fun.