I was planning on designing a Giant Anthropod track, which would be capable of modeling spiders, scorpions, crabs, etc. but I decided to hold off on it and see what the monster manual brought.
As far as this track goes, getting a feat for a circle is generally a bad idea. I know dragon does it, and is probably your reference point, but it is better to just give the effect, in this case a climb speed. however, a climb speed is worse than a flight speed, so the first circle probably needs a bit of a boost.
The static DC for the perception check is out of place. Abilities a creature possess should scale, not sit at a constant DC.
A "larceny or strength check" doesn't balance well. A larceny check is a dex check, with the possibility of adding your level if its trained. A strength check will never get such bonuses. Additionally, the same scaling that is used for saves is probably not appropriate for skill checks, and is certainly not appropriate for an attribute check. I don't even think attribute checks are a thing in Legend. The only one I can see is in Baptized in Rage, and that is probably an error. You also do not specify how long it takes, nor how much area, a spider can cover in web. This seems more like an environmental hazard that you are including in the track rather than an actual ability a monster should possess.
You also have an 8/day limit on the web attack. There are not per day limits in legend, the closest would be per scene. The entire 2nd circle doesn't seem to mesh well with the mechanics in legend.
I'd look at 3rd circle of discipline of the crane for poison use. They have once per [encounter] per two levels, swift action to activate, then 1d6 stat damage. However, stat damage is being removed, so it is better to just have the penalty you want to inflict.
Crushing is really out of place. Again, it is giving a feat, which is bad, and it doesn't really seem thematically appropriate. You might use towering as inspiration, but it should be its own ability.
The race itself is missing a property. You have darkvision, which is fine, but there is no second one.
The feat is not that good. Giving a bonus to a DC is something that should be done carefully. The most similar one is Explosives Expert, and that gives a feat bonus to a skill, and a +2 to DCs for a track. Giving +4 to DCs for a specific ability is not good.
Everything in legend should be just as viable for a player as an NPC. An ability to great existing terrain features to sit around in and battle with is useful for a NPC, but a PC who is likely travelling it will never get used. At the very least, you should offer an option between a web-weaver or a hunting spider, where the webweaver can make the static web and utilize it while the hunting spider gets some other type of bonus. Even that seems somewhat out of place.