If you check out some written instances of "only goes so far", you'll see it's relatively uncommon to follow this expression with an additional prepositional phrase.
Probably in consequence of this, it's often not easy to say which specific preposition is most appropriate in any given context. Taking OP's first couple of examples, I'd probably go for towards/in + gerund...
a: Having a college degree only goes so far towards/in reaching your goals in a life. (AmE toward)
...but in practice I'd most likely restructure things to avoid the trailing prepositional phrase...
b: When it comes to reaching your goals in a life, having a college degree only takes you so far.
As currently presented, none of OP's examples are idiomatically acceptable to me. But they contain many errors irrelevant to the usage under consideration, and would mostly benefit from significant rephrasing as per my (b) above. My general advice would be...
1: Consider restructuring so the sentence ends with "only goes so far" (or "only takes you so far")
2: If you can't or won't follow principle (1) above, use "[X] only goes so far towards [NP]"
(where [NP] is a noun phrase identifying some goal which can't be fully satisfied using [X])
Personal opinion: I don't like Sentence 1a; it seems to read awkwardly. Something about the don't only throws me. Here's how I'd rewrite it:
I don't just study a lot; I also play a lot.
Sentence 2a is okay, but I might be tempted to repeat the subject (this is not a required change, but some might feel it helps the readability):
I not only study a lot but I also play a lot.
Because it starts with not only, Sentence 3a needs the verb do. I would also add a comma and repeat the subject:
Not only do I study a lot, but I also play a lot.
As far as the negations go, I think Sentence 1b is better than Sentence 1a, but I'd still reword it like this:
Not only do I not study a lot, I also don't play a lot.
You don't really need the "but" in that sentence. The "not only" alerts the reader that a contrast is coming.
Some of these changes are more about improving the sentence as opposed to correcting grammatical errors. In other words, not only do they improve readability, they also improve the sentence's natural flow.
Best Answer
Yes, of course you can:
Which becomes:
Both of those sentences are grammatical. There may be a subtle difference in meaning, but the rule you give is certainly applicable.