In the book of vile darkness, there is a feat called dark speech.

DARK SPEECH [VILE] The character learns a smattering of the language of truly dark power. Prerequisite: Base Will save bonus +5, Int 15, Cha 15.

Benefit: The character can use the Dark Speech to bring loathing and fear to others, to help cast evil spells and create evil magic items, and to weaken physical objects (see Dark Speech in Chapter 2). Normal: Attempting to utter a word of the Dark Speech always ends in immediate death for a speaker who is not trained in its dark power. Fortunately, it is impossible to make someone use the Dark Speech if he or she is unwill- ing, because the language’s pronunciation is so exacting. Special: The character gains a +4 circumstance bonus on saving throws made when someone uses the Dark Speech against him or her.

Also, dark speech has some other affects, as mentioned below:

Dread: You speak in Dark Speech, causing fear to those around you that fail a certain dc, and depending on their level, hit dice and alingment. This damages your Charisma.

Power: You can increase the caster level of a spell, if it is evil it's cost does not change.

Corruption: You can reduce an object's hardness in half as a standard action. One time for each object, no side effects.

Dark Unity: You can create a hivemind of vermin, that do as you command for certain actions and a certain time. This drains your Constitution. More on hiveminds on the Book of Vile Darkness

Dark speech has no written form, and mortals that wish to utter even fragments or words of the language need the feat. Evil outsiders may not need it due to their nature. You can communicate with dark speech with some one knowledgeable of the language but you must be carefull not to harm yourself or the listener. Words like mercy, compasion, and generally good ideas do not exist in this language. There are some more details and roleplaying material on chapter 2 of the Book of Vile Darkness.

Edit: edited in order to avoid copyright issues.

Disclaimer: I have never played DnD 4th Edition.

There seem to be two different things this player is doing that are causing a problem for you, and I'm going to address them separately. I'll start with the simpler of the two.

Your player wants to contradict the rules.

He made a Dragonborn fighter, and since that moment he's been complaining about how he lacks low-light vision but our elf and halfing have it.

... he argued it was illogical it wasn't weak to fire powers since light sources should damage him, and so on.

He's also been asking for Rebuke Undead on the Cleric to become like the original where he can use it as a ritual and one-shot undeads ...

In these situations your player wants something he liked in other games, or because he feels it "makes sense" in the real world. For this, you're going to have to come down on the side of the rules here. The innate abilities of races, the separation of elemental damage types, and the design of combat powers are all a part of the game's balance. To give him these things would be unfair to the other players, who are working within the limits set up by the system.

Now, your player isn't going to like this, because he wants to do more "cool" stuff and his view is clearly that the system is holding him back in this respect. This brings us to the second part.

Your player wants to expand the rules.

Also, he seems to fail to understand Powers hold no real trole playing value, as he's been trying to cut ropes with fire at-will powers during sequences, trying to make the Psion use Far Hand or Far Push to impulse him thru gaps to den "exhale smoke" from his mind and use an at-will to burn wood, all of it on a skill challenge. He also tried to make the sorceror use Dragonfrost At-Will to extinguish lanters during a fight, that they could do my standing besides them and using a Minor Action.

Now, where above there was some real risk of your player unbalancing himself with respect to the other players and diminishing their fun, here the player is asking for things that can make the game fun for everyone. He's chafing at the idea that combat powers can't possibily be used out of combat. Why? Because it doesn't make sense.

You should allow the player to use his combat powers out of combat. There is a nice article preserved by the Internet Archive on this. The relevant tweaks are:

1. Make your players explain how the power fits. Sometimes just the name of the power alone will fit the situation, but allow your players flexibility. As long as they explain how that power represents the character’s approach and mindset, everything is going well.
2. Give them a bonus. Don’t give anything for at-wills, or your ranger is going to constantly be “twin-striking” in conversation. An encounter is worth +2 to a skill check, and a Daily is worth +6. Why so much? Because the PC is going to expend that power, and if they are expending a daily power to accomplish something, they should stand a good chance of success.

The gist of it is that powers do something, and they should certainly also do that something outside of combat. If he wants to try and burn an object with a combat fire power, then treat it as an attack on the object. Just because there's a non-power way of doing something doesn't mean that you have to stop the players from having fun with it.

Your player wants to have fun.

Your ultimate goal at the table isn't to enforce the rules as laid out by Wizards of the Coast. Your ultimate goal is to have a good time with your friends. If you deviate from the rules in little ways that don't harm the balance of the game in order to make it more fun, then so much the better to you.

If you adopt the bonus rule quoted above, share it with your players. You might find they'll do more interesting things out of combat with this reward. And they'll know that using an at-will won't have any mechanical benefit, but it could still seem awesome.

I find it's always best to err on the side of awesome.