Oh gosh... please don't remind me *LOL*. Well, first of all, people were really into Baywatch and Knight Rider ;). But then, one month after the wall fell in Berlin in 1989, he basically provided "Looking for freedom" as the OST. The song - and of course David himself - became super popular here. Read this article and watch the video to learn more: http://www.npr.org/templates/story/story.php?storyId=120191822

Sure! :) It is:
der Cousin (plural: die Cousins) -> mostly pronounced "Kusäng" / "Kusängs"
die Cousine (plural: die Cousinen) -> pronounced "Kusine" / "Kusinen"

No - not all verbs can be used as reflexive verbs! Neither can they in English! However, there are some that can be turned into a reflexive verb by using a corresponding form of "sich" - e.g. waschen - sich waschen ((to) wash - (to) wash oneself).

Grammatically, we distinguish real and unreal reflexive verbs. Also, sometimes an accusative or a dative has to follow! I will prepare a post about this soon and give you more info on my blog.

Meine Lieblingsstädte sind Berlin und Nürnberg.

Hallo - es freut mich, dass Ihnen mein Blog hilft/gefällt :)
Zu Ihrer Frage:
"Allerdings" kann vor allem auf zwei Arten verwendet werden:

1) Im Sinn von "jedoch" und "aber" (however; contradicting) -> z.B. Das Essen hat sehr gut geschmeckt. Allerdings war es nicht mehr heiß.

2) Im Sinn von "absolut" (indeed/it sure is.) -> z.B. Hat dir das Essen geschmeckt? - Allerdings! (Absolutely!)
Hast du von Tims neuem Job gehört? - Allerdings! (I sure have.)

Aww, thx! :)

"bei" can either be translated to "at" or "near". In both cases it requires the dative case - the Wem?-Fall. I don't think there's much more to add - if you have specific examples that you don't understand, please submit :)

Example:
Wo bist du jetzt/gerade/im Moment? - Ich bin BEI Tina (zu Hause).
Where are you now? - I'm AT Tina's.

Wo ist das Kino? - Das Kino ist (gleich) BEIM (= BEI + dem -> dative of direct article "der") Bahnhof.
Where's the movie theater? - It's near the railway station.

Thank you! :) I'm writing it down on my to-do list.

Be careful with "Donnerwetter" - usually it's not used to express surprise. It's mostly used to express anger - and similar to cursing. There are also expressions like "es gibt ein Donnerwetter" = There will be trouble.
It's all about the intonation used - so if used for "wow" make sure to make a happy face ;)
More interjections: http://www.bbc.co.uk/languages/german/cool/interjections.shtml

You can... But I only watch US TV series *lol*!!!

But of course Germany has some shows of its own - they're either not my genre (e.g. soap operas) or I just haven't checked them out yet. The only thing I could recommend is comedy like "Switch", "Stromberg" (German version of "The Office") or cooking shows ("Küchenschlacht", "Lafer, Lichter, lecker" etc.)

Hey there! I would go safe and introduce her as "Das ist ... (name)..., eine (gute) Freundin von mir." "meine Freundin" can easily be misunderstood as "my girlfriend", unless the context makes it clear.
I'm glad to hear you enjoy my blog and learning German. :)

Even Germans have difficulties with those verbs. In general, "tun" is to do and "machen" is make. But you cannot rely on that, cause there are several phrases like "Hausaufgaben machen" = "to do homework".
"tun" is usually used a lot in colloquial language. You will hear many people use the combination of tun + infinitive - but please do NOT use it often. It's really just a laziness and isn't considered to be good German. Here's an example: Ich tu dir eine Email schreiben. *cringe* -> Ich schreibe dir eine Email.
You should always try and use other verbs to sound better. Because sometimes machen and tun are used as substitutes.
e.g. Ich mache die Küche sauber. -> Ich putze die Küche.

I know, machen/tun are a confusing pair. If I were you, I'd learn expressions by heart which include one of the two. Stuff like "Hausaufgaben machen" "Es tut mir leid" etc.

You're welcome.

Haha, fantastic request! You really dug those Puddingbrezeln, didn't you? Here's a link to a German recipe -> http://www.kuechengoetter.de/rezepte/Kleingebaeck/Puddingstueckchen-Puddingachter-Puddingbrezel-809767.html
But I'll post a translation on my blog soon. You inspired me ;) And now I'm hungry *lol*

As in: Ich heiße...?
You can also say "Mein Name ist"

Dieses Buch gehört Tom literally translates to This book belongs to Tom.
The plural is: Diese Bücher gehören Tom. These books belong to Tom.
-> (to) belong to so. = jmd. gehören
It has nothing to do with the verb "hören" (to) hear; even though the past participle of hören is gehört. So don't be confused ;)

Another way to express possession is:
Das ist Toms Buch. -> This is Tom's book.
Das sind Toms Bücher. -> These are Tom's books.

Yes. You always have to use "in".
Ich bin verliebt in....

Yes, it is.
Example: Ich schaue deine Fotos an.

"Ich bedanke mich bei Ihnen..." :) Ich freue mich, dass ich Ihnen helfen konnte.

There are some mistakes. Here's a corrected version (btw - it's "der Brief" ;))

Sehr geehrte Damen und Herren,

ich wohne in....
Wir möchten gern einen Grundriss von unserer Wohnung haben und bitten Sie, uns einen Plan zu schicken. Vielen Dank für Ihr Verständnis (another appropriate expression: Vielen Dank im Voraus = Thank you in advance).

Gern geschehen :)