This is my attempt at a week 1. It may not be because the themers might be too hard to find. But it still shouldn't be any harder than a week 2, I hope.
I came up with this concept as part of my "So many rabbit holes" puzzle but it became a puzzle of its own.
Oh, by the way 29A is not a themer. It's just me going off on a tangent.
IF I'VE recalled correctly, iT WOuld gO NExt, right?: REmeMber. So RE34ME7890
Members of the phylum ofTEN noted for boNINEss: vertebraTEs. So RE34ME78TE
Gray area without the wEIGHT oF OUR certainty: penUmbrA . So RE3UME7ATE
This type of boating hazard iS EVEN worse on the norTH REEf: saNdbaR. So RENUMERATE