On the Faux Sunday morning talk show a Democrat congressman was explaining the memo. Chris Wallace objected, "But that's inside baseball!!". As if you didn't have to peel back the layers of this onion.
Now the republicans are big critics of the FISA courts. Not one peep in the previous sixteen years.
As for your last point, Trump is counting on the base not to read the memo or about it. Just making the charge is good enough for the base. No bother to actually read anything.
Counting on their stupidity? Trump BANKS on their stupidity!