Does Sandhi occur here for 十二？Sounds like shěr instead of shíèr to me.

why not 現在中午十二點？

現在是12點鐘。 is also correct

Can somebody help me understand the grammar here? 在 in previous lessons seems to generally be used as a marker of location translating closely to "is in", but here it seems to indicate time. I'm tempted to read 现在十二点 as now "is" (在) 12:00, but that would seem to use the word differently from how it was used in earlier lessons. Or is 在 not a verb here at all?