I am glad if it helps you anyway.

By the way, probably you didn´t belive that the book you have could have some common errors in its language...Well...Turkish is so full of traps that even educated natives have difficulty in commanding it. You can find some grammatically incorrect sentences even in the books of the famous Turkish novelist who won 2006 nobel literature prize. If you listen to any speech of our ministers live, it is hard to find a correct sentence!..

 if only is more like saying ah! bir than keþke even if they are often interchangeable:

Ah! bir gelebilse! = if he could only come!

Ah! bir zamanýnda yetiþse! = if only he arrives in time!

Ah! bir onu görebilmiþ olsaydýn. =if only you could have seen it.

Yes, keþke is necessary here.

The -se/-sa suffix has the same function as if-clause in English:

... olsaydým = if I were ...

When you place keþke before a verb suffixed by -se/-sa, it indicates an unfulfilled desire or a desire that cannot be fulfilled:

keþke ... olsaydým = I wish I were ...

O sigara olsaydým parmaklarýndan dudaklarýna giderdim=If I were that cigarette,I would go from your fingers to your lips.

keþke o sigara olsaydým...parmaklarýndan dudaklarýna gitmek için=I wish I were that cigarette... to go from your fingers to your lips.

 Just a little addition and a tiny correction to your try:

Keþke o sigara olsam...parmaklarýndan dudaklarýna gitmek için.

p.s. if s/he is smoking just beside you, you can use "bu".

1) Resimlere bakarak dinleyiniz 

   ( Listen?? to visual??? picture...)

-a.rak /-e.rek =>is a verbal suffix used to form an adverb from a verb (verbal adverb =>modifies the following verb which is often the predicate of the sentence/ under what conditions something happens or happened)  

Grammatically correct translation of "resimlere bakarak dinleyiniz" is "listen to it looking at the pictures", but the proper one is as toggle´s.

koþarak geldi = s/he came running

2) Dinleyiniz ve duyduðunuz kelimeyi uygun resmin altýna yazýnýz

   ( listen and write in /fill in  words accordingly??)

-d/tik/-d/týk/-d/tuk/-d/tük is a verbal suffix to form nouns from verbs ( a few of them are permanent nouns as in tanýdýk, bildik) that often used as an adjective (with personal endings) modifying the following noun.(verbal adjective)

duyduðunuz kelime = the word you hear

oturduðumuz ev= the house we live in

yaptýðým þey= the thing I did

3) aþaðýdaki cümleleri okuduðunuz diyaloða göre eþleþtiriniz

  ( read the following sentences and match ???)

(you know now how the -dik suffix works)

match the sentences below with/according to the dialog you read

4) aþaðýdaki soru kalýplarýný okuyunuz ve kendi cevabýnýzý yazýnýz

   ( read the following form of questions??? and write the answer yourself??)

soru kalýplarý = question patterns 

kendi cevabýn = your own answer

In Turkish it is a very common way to form a "noun compound" as in your example.(the first one modifies the following one) [often the folowing one with the suffix -i/ý/u/ü = soru kalýplar+ý / kendi cevab+ý+n (n=personal ending for 2nd sing.person) ] 

5) siz de arkadaþlarýnýzla örnekteki gibi yeni diyaloglar kurunuz

   ( Make up a dialog between you and your friend as if new??)

  - also I wonder why we use word de ( too,also) if we already use word ...la in arkadaþlarýnýzla

(Good question! you can find some stupid errors even in such books... "arkadaþlarýnýzla örnekteki gibi yeni diyaloglar kurunuz" was enough to give the full meaning.They probably tried to say: do it as your friend does/or do it together with your friend as the others do)

-d/ta / -d/te is locative suffix for nouns. (= in/on/at)

örnekte = in the example

duvarda = on the wall

tren istasyonunda = at the train station

...-t/deki gibi = as in ...

6) aþaðýdaki cümlelerdeki yanlýþlýklarý düzelterek cümleleri yeniden yazýnýz

  ( write new sentences to correct the following wrong sentences??)

(you know now the function of the suffix -erek)

rewrite the following sentences correcting the mistakes in them.

Yet another common error!!! yanlýþlýklarý !!! it should be  "yanlýþlarý".

yanlýþlýk = wrongness,incorrectness,etc.

 -lýk/-lik/-luk/-lük: (used to form nouns from nouns/adjectives)

mutlu+luk = happiness

saçma+lýk = absurdness 

Janissaries had been problem throughout the Ottoman history and there was no war won by the help of them.On the contrary, there were times that they refused to go to a war and stayed in Ýstanbul to loot the city in the lack of authority.That´s why it is called "Auspicious Incident" when Sultan Mahmut abolished the force in 1826.

sevmek also means "touch or stroke lovingly":

bir bebeði/yavru kediyi sevmek - fondle a baby/kitten 

seviþmek doesn´t mean "love each other" but "fondle each other"

Melek, I hope this will help you to understand the difference between kurmak and bir araya getirmek. 

kurduðun kelimeler  - the words you form/build

bir araya getirdiðin kelimeler - the words you put together

I wonder how could you put cats and dogs into the same category as terrorists!

This is just to be a little help to the learners.

 Here is one more Turkish option for  "I can picture" : "resmedebilirim".

"put together" means "bir araya getirmek".