A poem and a number sequence

Question

You wake up on the floor of an empty room without having any recollection of how you got there. The room is very dimly lit and it takes a while before your eyes are adapted to the darkness. There is only one way out of the room: a big metal door that appears to be closed. As you approach it you notice there's a number pad and what looks like a LED display on the wall next to the door. Getting closer you can see that there's a poem and some number sequence engraved into the wall as well:

                  

The number sequence goes:

$12,021,831,443,517,636,671,582,92,91,??$

And the poem reads:

ACCESS IS FORBIDDEN
SAVE YOURSELF NOW
BY THESE NUMBERS HIDDEN
AND SPUN SOMEHOW

BEGIN WITH THE FIRST
AND TURN IT ROUND
THE WORDS YET REVERSED
READ WHAT YOU'VE FOUND

REMOVE THE LETTERS
ALL BUT ONE
OBSERVE WHAT MATTERS
THEN YOU'RE DONE

MOVE ON TO THE NEXT
THE PROCEDURE'S THE SAME
READ OUT THE TEXT
AND TELL ME ITS NAME

ONCE YOU HAVE SPOTTED
WHAT THIS IS ABOUT
MAKE SURE YOU'VE GOT IT
AND LET YOURSELF OUT

You quickly figure out that the next number in the sequence is most likely going to be the code to unlock the door, while the cryptic poem seems to provide some clues on how to crack the pattern...

Can you escape?

Answer 1

The next number to the sequence will be ->

1151

If we do as said -

We have a sequence - 12,021,831,443,517,636,671,582,92,91,??

BEGIN WITH THE FIRST
AND TURN IT ROUND
THE WORDS YET REVERSED
READ WHAT YOU'VE FOUND

Let's take the first which is -> 12
Turning it around gives -> 21 -> TWENTY ONE
Reversing the words gives -> ENOYTNEWT

REMOVE THE LETTERS
ALL BUT ONE
OBSERVE WHAT MATTERS
THEN YOU'RE DONE

After removing all the letters from ENOYTNEWT except ONE, we get ONE

Lets try to do the same with other's by

021 -

021 -> Reversed -> 120
120 -> ONE TWENTY -> Reversed -> YTNEWTENO
Removing all letters except TWO we get TWO*(incremented by one)

831 -

831 -> Reversed -> 138
138 -> ONE HUNDRED THIRTY EIGHT -> Reversed -> THGIEYTRIHTDERDNUHENO
Removing all letters except THREE we get THREE*

443 -

443 -> Reversed -> 344
344 -> THREE HUNDRED FORTY FOUR -> Reversed -> RUOFYTROFDERDNUHEERHT
Removing all letters except FOUR we get FOUR*

517 -

517 -> Reversed -> 715
715-> SEVEN HUNDRED FIFTEEN -> Reversed -> NEETFIFDERDNUHNEVES
Removing all letters except FIVE we get FIVE*

636 -

636 -> Reversed -> 636
636-> SIX HUNDRED THIRTY SIX -> Reversed -> XISYTRIHTDERDNUHXIS
Removing all letters except SIX we get SIX*

671-

671-> Reversed -> 176
176-> ONE HUNDRED SEVENTY SIX -> Reversed -> XISYTNEVESDERDNUHENO
Removing all letters except SEVEN we get SEVEN*

582-

582-> Reversed -> 285
285-> TWO HUNDRED EIGHTY FIVE -> Reversed -> EVIFYTHGIEDERDNUHOWT
Removing all letters except EIGHT we get EIGHT*

92-

92-> Reversed -> 29
29-> TWENTY NINE -> Reversed -> ENINYTNEWT
Removing all letters except NINE we get NINE*

So, lets get to the last number

91

91-> Reversed -> 19
19-> NINETEEN -> Reversed -> NEETENIN
Removing all letters except TEN we get TEN

So,

The next number should produce ELEVEN in the reversed string. Hence, the answer can be 1511

How -

1151 -> 1511 -> ONE THOUSAND FIVE HUNDRED ELEVEN -> NEVELEDERDNUHEVIFDNASUOHTENO
Removing all except ELEVEN gives - > ELEVEN

So, the code is

1151. Reason being, when the words are reversed it gives respective number in words. And the original number is the lowest of all to follow the pattern. Thanks to @M Oehm for figuring this out.

Answer 2

I don't know if this one is right - I tried to follow the riddle and I got this:

seven - 99

eight - 9

four - 0

five - 9

six - 0(No number)

one - 90

two - 0
three - 99

zero - 09

What I did:

I converted it to words and turned it around. What happened is that almost all words, when turned around, have a number 9. Then I added it all up my answer was 315.

(wild guess)