And do you know if a student who gets a LAPL can then convert to an EASA SEP easily?
Yes, there's an easy conversion route.
(and the hours with a non-CPL instructor count?)
Of course, you don't have to hold a CPL to instruct under EASA.
And I presume an NPPL/LAPL only school still needs to be an FTO?
LAPL training must be at an ATO (once the transition period is over.)