General Details
At a glance this section doesn't look too bad, since it corresponds to what you've detailed so far, but it feels a bit scatterbrained. I'd rework the wording a little to give a better idea.
Actually touching something gives them very minute details of the object, somewhat better then human vision.
This wording is a bit iffy. I'd suggest something more neutral like: "allow them to perceive details that the vision of [[species]]-derived races might otherwise miss."
The idea is to convey strength without expressing how superior you think you are.
Gartagen hearing is distinctly average, their sense of touch allows them to 'hear' incredibly low frequency sounds and their natural hearing focuses on middle-low spectrum sounds. There is a secret language called the thumping language that's similar to Morse code and can be heard over long distances.
There's a similar issue here. I'd suggest making a seperate page for languages at some point and explaining 'Thumping' in a bit more detail. Also, this is not the sense of touch that hears, but the aural senses' ability to perceive vibrations, and presents some problems.
In snakes, this ability is largely because they have no limbs and their heads are in constant contact with the ground. It's much easier to listen to the vibrations in train tracks when you press your ear to them, after all. So either they have some sort of complex conduit system filled with tubes in their bodies to carry vibrations to their aural organs, or they have to press to something to listen in on the language. Or they have a more distributed sensory network, which doesn't make much sense in a race loosely based on Marsupials.
Which is very easy to intercept and disrupt by its very nature.
Obsessive Nature
The leisure feels a bit dull, but I suppose it's intentionally so. I'd focus on a family aspect a bit more.
Further most Gartagens will gossip like housewives during their leisure periods, using it to keep up on the activities of the people they know but have not seen recently.
More neutral phrasing such as "Many Gartagens are avid gossips, etc..." will make the article seem more mature. The concepts themselves are certainly unique, but a lot of your ideas seem to be drowned out by mediocre phrasing.
The first sentence Learning section has a grammar error that makes it hard to understand what you're trying to explain.
The pre-planning seems like a genuinely good idea, but might lead to a lot of metagaming. A person could always just say they planned correctly, and thrash the other guy at lightning speed while ignoring the penalty for thinking wrong. I'd suggest to remove it and find something better, because of these potential issues that might arise in RP.
Also, if there's a limit on how many plans a person can store, why would Gartagens bother trying to make up an infinite number of them? It feels arbitrary and sort of Pokemon-ish (You can learn Smash but have to Forget Quick Attack, etc...). Not to mention particularly difficult, if say, a bored Gartagen bank robber decides to plan about what he's going to do with his money and wipes out all of the plans he made for his escape with his partners.
Also, pain is a major stimulus that people can't just... 'ignore'. I'm aware they have differing biology, but this is a major ability for any race and sort of cheapens the 'heroic willpower' that we like to cultivate among most PCs. The baseline character shouldn't be able to turn into an instant badass death commando without some tampering or training. On the other hand, I'm willing to waive this complaint since Gartagens are describe as being physically weaker.
Boredom
This section's wording feels a bit unprofessional and immature. Please remove the quotations and give a more detailed explanation of what happens to a bored Gartagen, rather than using a comedic satire of post-modern art to provide contrast.
Cleverness
There are two definitions of clever. One is simply 'creative and quick thinking'. The other is a mental disorder. We will focus on the second.
wat
I'm really not sure what this section intends to express, although it sounds like the Gartagens have a unique form of Autism and ADHD that exists in the context in their differing psychological makeup. But the wording seems really ambiguous and the point is really unclear.
My advice is to take step back, and rework the concept from the ground up. And err... maybe change the name. Not that Clever is plain bad, but there are certainly jokes to be made at their expense.
More on Bonding in a bit.