The rule I learned was that when quoting the punctuation goes inside the last quotation mark for the reason you mentioned. "Shall I go to the park"? is wrong because the words inside the quote form a question. This is more obvious with q marks & exclamations than it is with periods. Quotes used for other purposes, such as enclosing a word or phrase that has a special meaning, require the punctuation to be outside the quote.

Terry, you're an outsider and one of those modern destroyers of semi-ancient verities. The outsider rule is "it goes in quotes if and only if it is part of the quote". The insider rule is that the punctuation goes inside the quote under all circumstances.

One notes that the insider convention is a product of movable type, not something truly ancient. It done to make typesetting easier, not for any grammar related reason. I say we should throw off the shackles of the hot lead mafia and be outsiders, using a rule that is truly grammar based and not just an artifact of the latest technology.

Bah!
As long as the new rules are clear, consistent, and lead to good outcomes, they can be adopted without a second though. The rule I advocate for gives greater flexibility, while retaining clarity(!); what’s not to love?

‘nother question for you: in my sentence above beginning “As long as...”, did I use too many commas? Or just the right amount?

I don't agree with Allie or you: you are both typolators and stand in egregious violation of what I call "the Sabbath principle." Typography was made for language, not language for typography. If typography cannot support the way people speak or otherwise communicate, it is typography that must change. And there's no reason we should be slaves to a convention based on an obsolete technology: the period-inside-the-quotes convention and all of its corollaries exists simply so that people setting type by hand wouldn't have to deal with little tiny bits of type or multiple punctuational possibilities.

Same principle with split infinitives and ending sentences with prepositions--why should we be slaves to the conventions of a language we don't even speak (Latin, in which neither is even possible)? In language, let euphony rule: "To boldly go," not "To go boldly." (And yes, I'm observing the old convention there because it doesn't change the sense of the quotations.)

"‘nother question for you: in my sentence above beginning “As long as...”, did I use too many commas? Or just the right amount?"
You're missing the spaces between the periods in the ellipses! '. . .', not '...'
When I was a kid (the 60's) the rule was that the word 'and' took the place of a comma because it marked the transition to a new clause, making a comma before or after it redundant. The rule changed to 'use a comma with 'and'' by the time I took composition in college. No reason for the change was given.
Smooth reading is supposed to be the goal of correct use of punctuation but there is a pedantic, arbitrary quality to some of the rules of comp. Remember the one about using a single dash, no spaces, in compound words while using a double-dash with a space before and after to note a parenthetical phrase in a direct quote? The editors of a few books I've read recently miss that one. Parentheses do not belong in quoted speech!

I don't see the sentence, but I'm a put-in-a-lot-of-extra-commas guy. You have to give people time to slow down, think, gather their wits, savor your point, breathe, and not, you know, rush hastily along through the sentence.

That's a good point about the parenthetical phrases. Which I'm sure I'll forget when the time comes to use it.

Trowbridge, it's the stocks for thee, thou syntactical Sabbath-breaker. The Gramaire Theocracy is almost ready, and then the dialectical heretics and morphological Quakers will be pelted with rotten vegetables in the public square.

The Brits and Aussies are both outsiders (not sure about Canada). And I wish we'd join them. Mark me as another 'quotation' renegade as far as the US is concerned.
If it's a quote, the punctuation goes inside. If it's not, punctuation goes outside.

I have been known to use the punctuation outside of the quote marks despite the fact that I know it is wrong.

The reason for a consistent typography is to allow for smooth reading. Commas were originally to indicate pauses in speech, with periods for a full stop. They later gained their use as a means to understanding; one should use them to split up the appropriate parts of the sentence. (I suspect that the reason it became allowable to have a comma before "and" was because of parallelism. Each respective category has its comma then, and there is no "odd one out" category. It also, once again, indicates a pause as in the previous sentence.)

However— and this is very important— there have been technical changes in typography that have changed the rules. Variable-width fonts are the primary cause of this. If you learned to type with a typewriter (or a fixed-width font), you learned several rules for type that no longer apply, such as the "two spaces after the period that ends a sentence" rule. The reason for that rule— the need to help visually indicate the beginning of a sentence— does not apply with a variable-width font, and two spaces looks extremely kludgy when you compare two otherwise identical paragraphs. (The change in ellipsis style is no doubt due to the same cause. …

Robin Williams— NOT the comedian— has several books on typography and design in the computer section of bookstores. She also illustrates why certain changes have been made to typography over the years (such as the two-space example I've listed above.) Her arguments are fairly persuasive, especially since her text is beautiful compared to some publishing examples I've seen.