Clarifying the usage of "hella"

Solution 1:

Wikipedia has an article on hella:

Hella is a word associated with Northern California used throughout the United States and Canada. It is a contraction of the phrase "hell of a" or "hell of a lot [of]". It often appears in place of the words "really," "a lot," "totally," "very," and in some cases, "yes." Whereas hell of a is generally used with a noun, according to linguist Pamela Munro, hella is primarily used to modify an adjective such as "good."

[...]

While intensifiers similar to hella exist in many colloquial varieties, hella is unique in its flexibility. It can be used to modify almost any part of speech, as shown below.
That pizza was hella good: hella modifies the adjective good, where Standard American English would use very.
I ate hella pizza: hella modifies the noun pizza, replacing a lot of.
I hella bought four pizzas: hella modifies the verb to buy, replacing really or totally.
I ran hella quickly to the pizza joint when I heard about the one dollar cheese slices from my friend when we were talking at four in the afternoon one Saturday night: hella modifies the adverb quickly, replacing very.

This does at least answer your second question (whether there were any other usages for this word that you were missing).

Judging from what I've heard of the word, I would say that your third example usage is pretty uncommon. A more normal usage would be:

You have to walk hella far to get to that subway station.

A crude proof would be to Google "walk hella"; the results show walk hella far, walk hella slow, etc. There are no examples of walk hella.

Solution 2:

Out of two native Northern Californians (myself and a friend), neither of us has ever heard usage 3. 1 is the most common and 2 is more unusual.

Solution 3:

As a native to the Bay Area, where the word first came into existence in Oakland, I've heard hella used and have used it myself as in example 3 a lot.

This is likely just a regional thing, as us East Bay-ers are intense in our love for hella and its less known and even more reviled couterpart, grippa. I'll try to explain:

Hella, I believe, is best understood from a sociolinguistic standpoint rather than a structural one. Hella first came to be as part of a pidgin that existed within the community speaking Ebonics. Ebonics is a spoken language, and as such hella's usage often feels instinctual.

In example 3, hella could mean several different things: You have to walk very far; You have to walk uphill; You have to walk through a bad part of town. Hella replaces what could appear to be a key part of the sentence, and when written, becomes confusing. However, meaning is conveyed when spoken.

I'll give you another example I used myself, just the other day: "I hella woke up this morning." Written out, it seems nonsensical and absurd, but I promise you every single person I was speaking to knew exactly what I meant, which was: "I was nearly late this morning because I slept through my alarm. I woke up very suddenly and had to race through my morning routine, forgoing coffee, in order to make it to work on time."

Hope this helps :)

Solution 4:

I feel like I've seen the third usage more and more often these days. It seems to be related to a similar shift in usage where "hella" itself is synonymous with "good". I can't provide sources beyond reporting that I've heard it used by friends. An example would be "Oh, that movie is hella", meaning "that movie is excellent".

(It's worth noting that it's never used with intensifiers, probably because we all instinctively sense that the possible phrase "That's hella hella" would be awful and should be avoided at all costs.)