Elan!
Makes my day that you've finally taken the plunge!!
I'd actually love some good books on football tactics and strategy - something a step above the "Dummies" books, maybe going through the history and evolution of formations, etc. All we get here in the States is aimed at providing parent-coaches with "drills" for youth rec-league practices.
Regarding your questions, I think you've got answers for most of 'em:
2) For the first friendlies, I play 45 minutes, sub out eleven players, and have the "second team" play the second half. Then I play them longer and longer as the preseason wears on, closing up with a final friendly about 10 days before the first "real" match in which I play almost every starter for 90 minutes.
4) Yikes. What is each position responsible for? Woof.
GK - Goalie - Uses his hands to keep the ball out of the net.
SW - Sweeper - Tends to be a central defender given a lot of freedom to roam around the back line, wherever he thinks he's needed. Not much used in modern formations, was very popular ten to twenty years ago, I think. I haven't used one in FM.
DC - Central defender - Typically tall strong players, who can muscle an opponent off the ball and win aerial crosses. Would tend to "man mark" the opposition strikers. Should "stay back" even when the team is attacking, though many managers send them forward on corner kicks.
DL/DR - Fullback - The "wide" defender. Typically a bit faster and shorter than the central defender. Tends to "man mark" the opposition wingers. Might or might not be given the freedom to get forward into the attack.
WBL/WBR - Wingback - Used in place of a fullback, and man-marks the opposition wingers.. but is expected to get forward and into attack much more. Attacks like a winger, defends like a fullback; therefore needs a ton of stamina.
DM - Defensive midfielder - I've been using this a lot in my games; its a midfielder who sits in front of my central defenders. He's a double threat - to intercept low passes for the opposition strikers, or to "close down" any opposition midfielder. Sometimes ranges sideline to sideline to break up attacks - but the fact that he's doing so means my defense can "hold their shape", and be better positioned for opposition attackers.
MC - Central Midfielder - Depending on your instructions to him, he's most likely a "box to box" midfielder, meaning he'll range from your eighteen to your opponent's eighteen. Ideally a hard working (Work Rate) player with plenty of stamina, responsible for both attack and defense. Two good central midfielders and you can really dominate a lower division!
ML/MR/AML/AMR - Wingers - By attacking the flanks, they either get one-on-one treatment with the opposition fullbacks, or they drag somebody else out of the middle. Typically very fast, good dribblers, who can cross the ball very well. Like an MC, though, a true winger is expected to track back and contribute in defense.
AMC - Attacking Midfielder - Typically the Creative playmaker whose brilliant Passing will rip apart the opposition defense, making chances for his teammates.. and ideally, one who can score Long Shots if nobody closes him down. Probably not expected to play too much defense.
FL/FR - Forward - Wide attackers, who will attack somewhat like a winger, but will also need to be able to cut inside and shoot. Not expected to track back in defense.
SC - Striker - Striker. Finishing. The man who bangs the ball into the back of the net, by hook or by crook. There's plenty of different ways to do it: the tall Target Man who scores plenty of goals on headers, the short speedster with blistering Pace, the artiste whose breathtaking Technique and Flair astounds and confounds defenders, and the goal-poacher who just hangs out in the box looking for rebounds.
If you imagine your attack looking something like this:
<pre class="ip-ubbcode-code-pre"> DL AML DC MC SCGK DC MC SC DR AMR</pre>
You can see how almost every player has three options in relatively close proximity to him: the DC has the other DC, the DL, and the MC... the MC has a DL, an AML, and the other MC... the AML has the SC, an MC, and the backpass to his DL...
A typical attack might build up as follows: GK to DC(r) to DR to MC(r) to MC(l) to AML to SC(l) to SC(r) - shoot, score!

.. but you can see on the little map that none of those passes had to be too long. That's not to say the DR didn't think about hoofing a long ball for the SC(r) to run onto...
If you're trying to design your own formation from scratch, that's the sort of thing you want to remember: keep people providing options for each other!
Look how the "diamond" midfield provides its natural linkages:
<pre class="ip-ubbcode-code-pre"> DL ML DC SCGK DMC AMC DC SC DR MR</pre>
5. I'd recommend starting with Ajax (Holland). The expectations will be very high, but in the Dutch divisions you should be able to stay in the top three pretty easily, while also getting a real challenge in the Champions League encounters. Plus they have such brilliant attackers that its always fun to watch them play.

Man-U is also a good place for beginners, and their debt structure will teach you to watch your finances, which is good practice for lower leagues.