> A low pound is good for British exports and tourism to the UK
Tourism perhaps, not that good for exports when we have to import all the stuff we use to make the exports and/or most of your exports are service based.
If 75% of the value of a good is from the imported raw materials and the rest is added by the processing applied in the UK then the remaining 25% benefits from the weaker Pound when the good is exported and the rest of is net unaffected by the change except to the extent that capital requirements effectively go up for the value of the intermediate goods in the supply line.
Absolutely but in the short term you have to buy your raw materials at a cost that is now much higher (temporarily) which can be a nasty shock for companies and something we've seen here.