Do these sound right & proper?

a) 2 X 16A immersion heaters in a heatbank

Both on one circuit on a 32A MCB, on a new 2X RCD split CU.
Seperately switched, in two locations viz:-
1) next to heatbank via 2 X switched fused spurs (?) with a 13A (plug
type) fuse in each
2) in neighbouring room via 2 X 45a DP switches (more convenient for
residents to control)

Queries
13A fuses for 16A immersions?
45A DP switches - wouldn’t 20A DP do and be a bit cheaper?


b) Is it a requirement (or worth doing) to cover cables on walls with
plastic capping prior to dot’n’dab plasterboarding and skimming? If
it’s been installed is there any way of checking apart from
destructive investigations?

cheers

JimK