I'd echo the use of at least a yellow filter, not only will it cut some of the light reaching the film but it will help render skies as something other than "pure white".
As for 100ISO film in the UK, I use it frequently and rarely with a tripod. But then I learned with Kodacolor 80ASA film on a medium format camera with maximum aperture of f3.5 and "guess the distance" manual focus. I still think that if I could do that aged five, the average adult ought to be able to....but am frequently proved wrong. Having said that, I still cannot reliably tie my shoe laces so I guess we all have different skill sets.