Cellphones were big 400 years ago. It's probably more unusual that Malloy knows about them than Charley doesn't. I agree that the rest is very convienient.Spoilers for S03E06, "Twice in a Lifetime"...
I find it highly implausible that Charly wouldn't know what a cell phone is. Surely they would have come up at some point during her education.
I also find it highly implausible that Ed and Kelly were surprised by Malloy's wife and kid(s), because they'd seen his obituary.
I also find it highly implausible that the spot where Charly and Isaac needed to drill just happened to be underneath the one house in Southern California with a basement, which just happened to be vacant.