So firstly, you don't need a masters degree in clinical psychology in order to do the doctorate. However, you couldn't work as a Clinical Psychologist without completing training up to doctorate level. You could go into other work, such as as a psychotherapist, after completing an MSc in clinical psychology, however, this would involve further professional training in that field. Psychology and psychotherapy are 2 completely different fields, so have different training routes.
As for studying abroad, you would need to check with the BPS/HCPC to see if any training you have elsewhere would be accepted here for registration purposes.
I'm curious about why you want to do this particular masters degree if you do not wish to become a clinical psychologist. Career-wise, it may make better sense to do something else.