cipher - This is an opportunity. Can you take it?

The first thing you hear on awakening is the clock. It sounds just like the one you have in your room. But what you see defies what you hear.

You've never seen this room before. You don't remember how you got here. The last thing you can remember is that your mission went horribly wrong...

Wincing, you get up and survey the scene in front of you. As you reach up, and feel a painfully large lump on the back of your head, a crumpled piece of paper falls out your top. You tuck into your pocket, thinking it will be important later. You look at the door and don't need to go over there to know that it's locked. Here's the room you see (click for a better view)

Can you escape?

This will be important later:

QNW

NOTE:

I created all the images from scratch though I occasionally used an online image in the making of my images which I don't claim as my own. If you find something odd in an image which doesn't appear to be a clue, it's probably an unintentional error which (probably) won't affect the puzzle.

Answer

Solution:

On the enlarged picture, there is an open book on the shelf with something that looks like an imgur link.
I made a screenshot about that gif, and typed the letters, so here they are for copy-paste:

fkx wpwax iggqkl mg zighva gsfhhixxdu
pshc wvsnfz erw ldmrd scemg'qky jhmjh whea jshv plsnyd
5gugo.lrk

fol'zf zvcbme wu tyqt fvod qu kplc jmcd ug apcu
i'd i ecbbcm bulnk
q'ws sewb zcb cccfg ao vadowe
wqor
ahv xbgz cflf hv lzdf
tpnu bjal ow mydsojqpb
zo pwv yuon ppk tutp
uwte pwv vhvv tfta

I tried decoding this as a Vigenere cipher with the key given in the hint ('QNW'), but it fails. Maybe that comes to use in a later step.

@Strawberry suggested using 'sweet' as a key. (I suppose it comes from the crossword to which there was another link on the table on the enlarged image).
That one gives:

not sweet enough to decode completely
look around and think again'you found some food though
5cqnw.png
mwp'vb gdgxil ey puxb jrkk yy glsk niyk ck wljc
m'z e lkfxyt jyhjr
y'ao olef vyi kgybn is rwkwaa
sxwv
wdc ffcv jnpb dc tdzb
axrq xqip ks tghokqytx
vv xar ubwr llr bypl

bexa ldd zdrc bjpw

The second key for the second half of the message is 'haribo'. That must be sweet enough indeed. I kind of bruteforced it, supposing the message starts with either 'you've' or 'you're'. It reads:

you're locked in this room it will blow up soon
i'm a double agent
i've left you clues to escape
find
the pass code to live
find time of explosion
so you know how much
time you have left

Maybe the time of explosion is 10:30 as written on the calendar. So we've around 20 minutes left. We have to hurry, but also, need to think with a calm head. What might the pass code be?

Ok, so in the first decoded version of the message, '5cqnw.png' suggests imgur again. Changing 'qnw' into 'QNW', we get a valid imgur link - thanks for the observation, @Ankoganit. The new image contains a carton of a cereal titled "NEW SWEENEES" which seems to be compass-directions. As the crumpled piece of paper had a compass on it, this should probably used on that. Starting from the specially marked box, we get: II, III, II, V, IV, V, IV, III, I, IV, III,
which are all roman numerals, the ones for which the directions were underlined read 3413.

---

EDIT FROM OP

This answer is almost completely correct, but I'd just like to add a few things that were missed out, or not clearly stated.

First of all in the first room, the newspaper headline says Another Bomb Murder. This is another clue that the room will explode.

When the image is clicked on new things appear. The newspaper changes to a Crossword with ucBTN.jpg written. Changing the end of the imgur link gives us:

The first clue is 'grain turned sugary'. Grarin is wheat. Wheat turned sugary is sweet
The second clue is 'A 3rd exists'. To be is to exist. Is is 3rd person of be.
The third clue is 'Grants power of entrance', which is a key
The last clue is 'Common determiner'. The

Rearranged this gives us Sweet is the key

The other thing that changes is that the book on the shelf changes to give 2yRkA.gif. Changing the link gives us a GIF of a book. A page flips over to give the text that @elias kindly wrote out.

Using 'sweet' as the key gives

'Not sweet enough to decode completely, look around and think again. You found some food though. 5cqnw.png.

So sweet isn't the key. But in the far left cupboard in the enlarged image is this:

It's hard to make out in the shadow of the cupboard but you can just make out the 'H' in Haribo. So 'Haribo' is the sweet that is the key.

Using Haribo to decode the cipher you learn that you're locked in the room which will explode, but a double agent has left clues to escape.

Changing the imgur adress to 5cqnw.png gives nothing but by using QNW, we get a new room. This has a cereal packet:

This has another clue that the room is going to explode with the explosion around new. So 'New Explosion'. The name of the cereal is NEW SWEENEES.

Interestingly =this only contains the letters NSEW which are all part of the compass. Under the packet is says 'Cereal that directs you'.

This tells us to use the NEWSWEENEES as directions. On the map which fell out or top.

There are four letters underlined in the cereal packet, the second, fifth, ninth and eleventh.
On the map those underlined letters give us 3413

On the table is an envelope this is an unsubtle clue to the postbox in the door. In the enlarged version we get this:

By typing in 3413 you escape! The explosion happens twenty minutes later (the calendar) after the area has been evacuated after you tell the police.