Hi Voodoo,
I went to ShopRite so that I could taste Jalapenos.
I went to ShopRite so as to taste Jalapenos
I went to ShopRite enough to taste Jalapenos ---> [doesnt sound correct to my ear]
It was so cold outside that I had to go inside the shop
It was cold enough for me to go inside the shop. --> [not sure about this one]
It was cold enough so as to lead me to go inside the shop. --> [haha sounds funny to me. I would never use this in my day-to-day conversation ha-ha]
Yep, your first two sentences work just fine: "so that [subject] can/could/would be able to/will be able to/may/might" can be used interchangeably with "so as to" or "in order to" -- as far as I can think, at least.
"Enough" suggests "to such a degree that..." -- so as you suspected, your third sentence ("I went to ShopRite enough to taste jalapenos") doesn't work. I guess the primary problem with it is that going to ShopRite is something one either does or doesn't do -- there's no variable degree in it. But for example, if you inserted the concept of frequency into the sentence, you'd get in that element of variable degree, since one can do something never, once in a while, semi-frequently, very frequently, all the time, etc. -- there's a whole spectrum. So we certainly COULD say,
I went to ShopRite often enough that the cashiers all knew me by name.
This one
It was cold enough for me to go inside the shop. --> [not sure about this one]
is interesting. I'd say it doesn't *quite* work, though it also wouldn't seem weird if you said it. The thing is, consider these sentences (all acceptable):
It was cold enough that my toes turned blue. / It was so cold that my toes turned blue.
It was cold enough that you could see your breath in the air. / It was so cold that you could...
It was cold enough that the county cancelled school for the day. / It was so cold that the county...
In all those examples, the outcome is something over which you have no control -- you don't get to make a choice in the matter, so from your perspective it's just that the degree of coldness led to these outcomes.
But when you say, "It was cold enough for me to go inside the shop," it's a different situation, in that you got to make a decision with respect to whether to go inside the shop, so it wasn't just a situation where the degree of cold led automatically to your going inside the shop. When there's that element of choice in there, or when the outcome doesn't follow automatically as a result of the degree of cold, then using "for" suggests that some condition has been met that
allows you to do (or justifies your doing) something you want -- as though you've been waiting for that justification. For instance, I might say,
"It's warm enough for ice cream" --> I've been wanting ice cream, and I've been waiting for it to get sufficiently warm to justify my getting some.
"It's sunny enough for a picnic" --> Hooray, finally we can have a picnic!
"It's cold enough for a fire" --> We've been freezing and waiting for it to get cold ENOUGH that it justifies our lighting a fire.
But in your example -- "It was cold enough for me to go inside the shop" -- I think the situation is more that it was so cold that you HAD to or decided to go inside the store; it's not that you've been waiting outside wanting and wanting to go inside, and just waiting for some sufficiently cold checkpoint to be hit. So in that case I'd probably say instead "It was so cold that I went inside the shop" or "It was cold enough to drive me inside the shop" or something like that. This is a very subtle distinction, though, one I'm confident you would never have to make on the GMAT.
And finally, you're right that you wouldn't want to say
It was cold enough so as to lead me to go inside the shop. --> [haha sounds funny to me. I would never use this in my day-to-day conversation ha-ha]
The "enough" and the "so as to" form a redundancy in that sentence.
Best,