Second - my friend and me have tried over 100 passwords, and nothing...
What come to my mind is - is there really no great and reliable hacker on this entire forum, that could crack this problem??
Cuz, to be honest, i have no intention leaving bitcoin to just float around...
You are getting a lot of nonsense advice from people that are participating in a signature advertising campaign. All those people with advertisements at the bottom of their posts are getting paid by advertisers to create posts on the forum. They generally don't care if their advice is any good. As long as it looks like they are participating in a conversation, the advertiser pays them.
Some things to be aware of...
4 years ago blockchain.info did NOT use a seed phrase. So, if your wallet was created that long ago, then there is no seed phrase to find. You can simply click the "ignore" link on the left side of the post of any user that has suggested anything about a seed phrase, a mnemonic, or a 12 or 24 word phrase. Those individuals clearly don't know what they are talking about and are simply wasting your time.
While blockchain.info did provide a method of creating a backup of your wallet, it was not possible to import that backup into MultiBit. You can simply click the "ignore" link on the left side of the post of any user that has suggested trying to do that. Those individuals clearly don't know what they are talking about and are simply wasting your time.
HCP is an experienced, knowledgeable, and helpful member of this forum. Even though he has a signature advertisement, I would suggest that you do NOT click the ignore link in his posts, and that you answer his questions and pay attention to his advice and suggestions.
All that being said...
It sounds like what you have is an old blockchain.info wallet ID.
If blockchain.info is willing to help you, it should be possible for an employee of blockchain.info to find your wallet in their system using that wallet ID.
The bad news is that when you create a blockchain.info wallet, it is encrypted with your password before it is sent to the blockchain.info servers. Without the correct password, it won't be possible to decrypt the wallet, and if you can't decrypt the wallet, then you won't be able to access the bitcoins.
You are certain that the email doen't have anything in it that might have been a disguised password? It seems really odd that your friend would knowingly set a password up, and then not give it to you in some form. Perhaps he sent a separate email around that same date that had the password in it? Or perhaps he gave you a piece of paper with the password typed or written on it?
If your friend has a common algorithm that he uses to create passwords, then it might be possible for a computer program to crack it. If your friend typically creates long passwords (more than 10 characters) AND generates them completely randomly (such as with a password generator), then it is extremly unlikely that you'll be able to access the wallet without remembering or finding the password somewhere.
Note that the more likely facts that your friend can remember about the password, the easier it will be to crack. Every tiny detail helps reduce the effort needed to crack it.
For example, when thinking about how he might choose a password 4 years ago:
Can your friend say that the password would DEFINITELY be more than 3 characters long? 4? 5? 6? 7? 8? etc... What is the biggest number that he can say it is DEFINITELY longer than?
Can your friend say that the password would DEFINITELY be less than 100 characters long? 50? 30? 20? 10? etc... What is the smallest number that he can say it is DEFINITELY shorter than?
Can your friend say that the password would DEFINITELY have (or DEFINITELY NOT have) lower case letters?
Can your friend say that the password would DEFINITELY have (or DEFINITELY NOT have) upper case letters?
Can your friend say that the password would DEFINITELY have (or DEFINITELY NOT have) any numeric digits?
Can your friend say that the password would DEFINITELY have (or DEFINITELY NOT have) any punctuation or other special characters?
Can your friend say that the first character DEFINITELY would (or DEFINITELY would NOT) be any of those types (lower, upper, number, special)?
Can your friend say that the last character DEFINITELY would (or DEFINITELY would NOT) be any of those types (lower, upper, number, special)?
Can your friend say that the password DEFINITELY would (or DEFINITELY would NOT) include any real words, names, dates?
If it might contain any real words, names, dates, can your friend say where in the password it could have occurred (beginning, middle, end)?
These are just some examples of the types of details that can make cracking the password easier. If there is anything else at all that your friend can say for certain (or at least very likely) about the password, it will make it easier to crack it.
Does your friend still have access to the computer that he would have had back then? If so, then it is possible that the password is saved in his browser settings (people frequently choose to let their browser save their passwords for them).
4 years ago, Blockchain.info also provided a method to have your wallet file emailed to you. It seems unlikely that your friend would have done that, but if he still has access the the email account that he used back then, it might be worth looking through some old email messages, or the downloads folder on the computer.
my friend and me have tried over 100 passwords, and nothing...
-snip-
A password cracker may be able to try HUNDREDS of THOUSANDS of passwords per second or more.
Unfortunately, a password that is purely random, AND 11 characters long, AND randomly chooses from upper, lower, digits, and special characters has 5,062,982,072,492,057,196,544 possibilities. Even if the password cracker could try a billion passwords per second, it would take on average 80,218 years to crack such a random password.
Now imagine that you knew for a fact that the password was no more than 8 characters long and all lowercase, except for the last character which was definitely a digit, and the second to last character which is either a digit or a lowercase character. Remember only those details, the number of possibilities drops to 111,209,679,360. In that case, a password cracker that can try a billion passwords per second would take on average less than 1 minute to crack such a password, and a password cracker that tries 1,000 passwords per second would take on average less than 2 years.