I feel like I should be able to answer this, but I can't at this hour. I can answer your questions with "it depends".
You may not use your science degree (what majors or subjects do you have in mind?), but I'm sure there'd be ways to make it work or use things learnt from those classes.
To be frank, there's truly very little that you learn at university that prepares you adequately or well for the real world.
Proper science can be pretty brutal (not psych or history/phil of science), but I've known people to make it work. Some enter doing B.Sc./LL.B. but end up doing B.Sc./LL.B. with an Honours year in science. Some go 'off the rails' as it were and drop law to pursue science too. Some graduate with flying colours in both, with or without science honours, and utilise that scientific knowledge in some manner relevant to law or use that thinking or skills in some way.
Some people think about IP, environmental, med, crim, etc. law or whatever (e.g., policy, journalism) prior to enrolling or during their studies. That's great for giving yourself drive, but you also have to manage your expectations and moderate your ambitions/goals - not too low, not too high, not too narrow, and not too broad. Life doesn't work out as planned for most of us and you have to be flexible about it or live one day at a time.
It really depends on what you're interested in / makes you happy, what you want, what you put in, what you'd like to get out, and what you actually get out of it all (e.g., all Hs in your courses? This precludes many from ever being competitive for clerkships at top-tier firms, for instance).
So basically, that was my way of suggesting that science/law isn't 'redundant'.
Difficult is pretty subjective. I'm sure you're a clever cookie, and your being offered law will only validate that all the more. In any case, I'm sure you'd manage that workload.
This is all over the place. Sorry for that but I hope this somehow helps.
