Normally stock splits (or, more broadly, "corporate actions") are incorporated into things like Google Finance to avoid skews from stock splits, rights issues, stock reissues and so forth skewing the historical results.
So I think the OP is right.
Correct. 2-1, 3-1, then 2-1 early on. So there's a 12 to 1 ratio at play there. Initial day's closing was 18$.
Yea, I don't believe the actual opening price was $1.73
It’s not. But the equivalent opening price if you factor in the stock splits - which would have multiplied the shares you bought at opening - is $1.73 per share.