Currently have feed to 16A rotary isolator, I’m gonna come of this with 2.5mm to a socket then to a fused connection unit to feed 2 lights if lid this ok
yes you would need to go to a fcu first then to socket then another fcu to switch lights but others will say different the first one is to prevent overload on the isolator.
Depends what fuse is feeding the isolator, I use 32A isolators even for lighting because there is more space inside them.