A single receptacle on dedicated branch circuit shall have ampere rating not less than that of branch circuit (A refrigerator on a 20 Amp line shall have 20 Amp receptacle) . –210.21(B)(1)
Steel plate needed to cover holes in wood that are 1¼" or less from edge. - 300.4(A)(1)
If you want to replace a non-ground type receptacle or a two wire NM cable without a ground, then replace with another non-grounding type receptacle. Or a GFCI receptacle , marked ‘No Equipment Ground’ or Grounding type receptacle , if GFCI protected & marked ‘GFCI Protected’ and ‘ No Equipment Ground’.- 406.3(D)(3)
A recessed light (High Hat) must be air tight if it breaks the insulation barrier.