Minisport sell a LHD rack. They should be able to advise you on any issues, tips and tricks when fitting, above what is already in the product description.
https://minisport.com.au/products/mini- ... e-importedBMC Australia included LHD option in the technical design of the round-nose Mini. I don't know if that extended to the later Clubman/Leyland vehicles.
The following diagram shows the brake and clutch arrangement for RHD and LHD. In your case I suggest you refer to YDO6 (Cooper S) which has a PBR VH44 power brake booster that remains in its original spot on the RHS flitch panel and has a pipe coming across the firewall from the master cylinder. The clutch also has a pipe coming across to the slave cylinder.
Attachment:
AYG5235 Arrangement Brake Clutch MC and pipes subset.jpg
What do you mean about the accelerator pedal not working?
I can't comment on the wiring loom for LHD.