Federer's a terrible tactician
Think about what you're saying here - you look pretty daft, mind you, you are calling the most successful player in the game a terrible tactician. Federer is a superb tactician. Maybe if you think "he's a terrible tactician because of this and that and this" you forget to see the good tactics that he does employ; this year he has won several titles (and on different surfaces, different countries, different opponents), each match, each opponent, each tournament, each surface is different.
If you believe Federer is a terrible tactician - then the likes of Nadal, Djokovic, Murray, in fact... anyone out there, cannot even have the noun tactician applied to them. The intelligence Federer plays with on court (most of the time, and this will be explained later) is remarkable; even at his late age he is still ahead of pretty much everyone in how he plays tennis on the court.
His losses to Nadal early on in his career are perfect examples of this
You do not prove something (i.e. Federer is a terrible tactician) by giving an example, rather you disprove something by giving an example; in mathematics it is called a counter-example. There is no logic in saying what you have quoted.
The losses to Nadal indicate, perhaps, that Federer did not employ the best available tactics against Nadal - that does not defeat the notion that he is a superb tactician, just that against Nadal, he didn't (or doesn't) employ the best tactics.
Saying that - Federer played well against Nadal in numerous matches earlier on; assume he played well in the matches that he won and let us look at the matches that he lost:
Dubai 2006 - was up a break in the first set.
Rome 2006 - Had match points.
French Open 2006 - 6-1 1*- 0.
French Open 2007 - 17 break points.
Monte Carlo 2008 - Up a break in... each set.
Hamburg 2008 - Up 4-0* in the first set.
Wimbledon 2008 - Up a break in the second set, 2 points away from winning.
These do not illustrate or "prove" that Federer is a superb tactician, rather they just show how Federer was capable of using the correct tactics to build a lead (or come back from a defeat - Wimbledon 2008, Hamburg 2007) against Nadal. It shows that Federer can employ good tactics even against someone who you believe proves that Federer is a terrible tactician, which is clearly not the case.
It may be the case that Federer is a terrible tactician against Nadal specifically - but given his success against Nadal and even in the losses (look above), that really isn't the case; and if you believe that, then it's simple to fix: watch the matches, you will see how many times Federer gets ahead.
He absolutely refused to adapt no matter what
This isn't necessarily a bad thing - against many other players he has refused to use other tactics that most players use (i.e. the way he went after Roddick's serve in the period 2003-2007, no one else did, at all). It could mean he is working on a proactive style that he thinks is good enough to win against the opponent; be it Nadal, Murray, etc.
However, he HAS adopted. He is one of the best "adopters" on the tour; his success this year and last year (later) show how well he adopts to anything; the poor blue surface in Madrid, slow courts in Indian Wells, fast courts in Dubai, medium courts in Rotterdam, etc, etc,
He just needed to actually not play like a stubborn idiot.
Easy to say when you are watching from home! Perhaps some credit has to go to Nadal? Surely he had a say in the matches, too..
instead he allowed Nadal to beat him over relentlessly by staying way too far back, while never forcing Nadal to serve into different directions, especially on the AD court.
I completely agree with you - but this in part is explained by what Nadal is so good at; he makes you play with him and takes you to his level, as explained
HERE.
People overrate Federer's tactical abilities. He has two tricks, the slice backhand that he literally abuses over and over again against players like Roddick, Berdych, etc. who cannot properly deal with it, and his inside out forehand. His variety is completely overrated. Period.
If that's what you think "tactical abilities" equal, then clearly you will see it that way. The two shots you listed are listed as "technical ability", not tactical; such a misconception is common. I could list 100+ "things" Federer has "done" to illustrate superb tactical ability; but these would not be "technical ability", they would be "tactical ability". So a short slice backhand may be a tactic in some context, but by definition it is a technical shot!
The last "allcourt" style Federer played was early in 2005.
Completely incorrect and I almost feel sorry for you if you think of tennis and of Federer this way - this kind of view explains how tennis pundits love watching Federer and hail him for his all-court game, yet tennis viewers feel he does not have an all-court game.
All-court changes with time - what was defined as an "aggressive baseliner" in 1990 and what is defined as an "aggressive baseliner" in 2012 is totally different; Federer's all-court game has been apparent in many of his victories, but a good example to illustrate that he definitely has an all-court game, is the Madrid match vs Raonic. From the baseline he was getting nothing - Raonic was just firing either a winner or Federer was making an unforced error, so he started serve and volleying and gradually moved up even on Raonic's return.
Such an idea is rare on any surface - to make the big server move back by moving up on his service games, rather than the usual way to think "I'm going to out-grind him and move even more back to return his games".
his one dimensional style of play of glueing himself onto the baseline has hurt him plenty of times.
Against Djokovic, Nadal and some other top players, yes, of course; but cannot this be said for all top players against respective top players? Against the very best your potential "problems" with your game come out due to the pressure and style of your quality opponent!