Understanding どう転んでもいいように高校だけは出ておきなさい

Question

Dad tells his son who is in high school this phrase

どう転んでもいいように高校だけは出ておきなさい

I have difficulty comprehending the whole meaning of this phrase.

どう転んでも is some kind of idiom meaning "no matter how you do" right?

What いいように means here? According to this question, it can either mean "like/as good" (ie. "in a good manner") or "in such way that (to achieve one's own) good." I don't know which meaning fits in this context.

I know that 高校を出る means "to graduate from high school." But when だけは replaces を, how the meaning change? "graduate only from high school"? I'm confused what は is doing after だけ. If I interpret it as a contrastive は, then it makes だけ redundant. Is it a topic marker?

This is how I understand the overall meaning of this phrase

No matter how you do, just graduate from high school for your sake!

Did I get it right?

Answer 1

いいように

ように here means "in order to". So your second interpretation is correct.

だけ vs だけは

I personally don't differentiate between contrastive and topic marker for は, so I don't know how to answer that question but, だけ means "only", whereas だけは means "if nothing else". In this case,

高校だけ出ておきなさい

would mean "Finish up to high school only (do not go to college, or anything further)". While,

高校だけは出ておきなさい

would mean, "If nothing else, finish high school (whether you go to college after that is not important/out of the scope of this conversation)".

So the whole sentence would be something like

If nothing else, finish high school, so that you can keep your options open.

(I'm assuming どう転んでも refers to the listener's prospects after high school.)