particle と - ~たらいい、~といい, hope, temporal syntax and over-literal readings

So I have two problems that are difficult to explain about the ～たらいい and ～といい pattern, the first problem is as follows:

I have been reading Susumu Kuno's “The Structure of the Japanese Language”, a book probably too advanced for someone of my reading level. In chapter 15, the book covers the conditional 「と」 particle and the differences between it and 「たら」 and 「なら」. One of the examples (with formatting edits) given is:

(5) “It is pleasant when/if it rains”

a. 雨が降ると気持ちがいい。 ○

b. 雨が降ったら気持ちがいい。 ×

c. 雨が降るなら気持ちがいい。　×

It then goes on it say:

“Sentence (5a) represents a habitual antecedent-consequent relationship 'I feel refreshed whenever it rains'. Example (5b) is ungrammatical because the time referred to by 「気持ちがいい」 “It is pleasant” syntactically precedes that referred to by 「雨が降ったら」 'If it rains', while in reality it will become pleasant after it has rained. Example (5c) is ungrammatical for the same reason.”

What is meant here is that stative verbals, such as いい, refer to present time whilst non-stative verbals, such as 降る, typically refer to future time.

So I'll take a phrase that I just read a short while ago:

「見つかるといい」　(I hope you find [it]). → 「見つかったらいい」

This website states that ～たらいい is the same as ~といい, but technically this does not make sense according to Kuno's temporal syntactic observation. Is this phrase special for some reason?

My second problem just bugs me, is more of an English language question and comes from literally translating stuff in my head:

「見つかるといい」

If I translate this less literally and then adapt it, I get following phrase “It will be good if you find it” → “It would be good if you find it” →”I hope you find it”. However, If I try to infer the meaning while keeping the word order:

“If you find it, it will be good”

This sentence is grammatical, albeit a little awkward. More importantly, to me, the meaning of “hope that” seems to be lost when this ordering is kept, Is there a reason that, in this case, the meaning is lost in English?

Answer

First, 雨が降ったら気持ちいい is no problem in terms of syntax. However, it could be, in a sense, strange when it stands for a future tense, not a situation where it actually is raining or has just rained, because it means that you find yourself feeling pleasant once it happens to rain.

Practically, …たら is versatile and you can use it instead of …と or …ば, apart from minor nuance.

(Incidentally, it's no problem if it's an assumption like 気持ちいいはず or an expression to persuade other people e.g. 雨降ったら気持ちいいって or …気持ちいいよ？)

雨が降るなら気持ちいい is parallel to the above. It means that you sense physically pleasant if it's supposed to rain, which is somewhat odd. Maybe it could, depending on situations. If it was 気分がいい, it would be fine.

If you find "hope that" more or less off, you can quit thinking so. They are two different things, if close.