Hi Aesamira,
I am a student currently studying (well pretty much now finished earlier because of COVID-19) British A-Levels (CAIE) in Thailand who applied to the UBC Faculty of Arts, I was admitted into UBCO's Faculty of Arts, so perhaps I can help?
Your questions are pretty good and fair, in fact, I had some of the same questions and concerns as you for a few years prior to my application.
(Please take these answers with a grain of salt as it is my own perspective and guess since I did not apply to Sauder)
Here are my answers:
1. There are no specific grades for UBC, at least to my knowledge as it was never specified. I did find it strange but however UBC does not have a ‘fixed’ A-Level grade criterion for admission, since it changes every year, perhaps due to number of applications? Of course, that still means you have to achieve high grades in A-Levels nonetheless (i.e. ABB, AAB, AAA, etc., those grades have really good chances), the higher the grades, the higher the chances.
As for GCSEs (I did IGCSEs, basically the international version) a minimum of 5 C's is still somewhat sufficient for UBC I am sure, just like any other university, even in the UK. I personally got 8 IGCSE's between A*-C, as the same for A-Levels, the higher your grades, the better your chances.
2. My advice would be to take courses related to what you want to study in Sauder, for example, if you want to do, for example, Bachelor of Commerce, you may look into taking courses in Business, Economics, Mathematics, etc. for your A-Levels. These courses may even act as a prerequisite or show that you have a well-balanced foundation for your possibility to study at UBC Sauder. Also, with your high grades there may be a possibility that you could get first-year credit.
3. I am not sure what the international acceptance rate is, but I remember that every year UBC releases a document specifying how many students admitted into what faculty, domestic and international at both campuses. I am sure that may give you a good idea and perspective of how many people are admitted into your degree of choice and the overall percentage.
4. I doubt there is any particular extra-curricular activities or work required you can do that would win you an advantage. Remember that UBC cares about how you write your personal profile, not only about what you did in a “bullet-point style”, (e.g. “I did this (blah blah blah) for 2 years and that for 3 months and blah blah”).
Instead, talk about how the activity’s experience has changed you, what you have learned and taken aboard to become the person you are now and etc. Since that style of writing shows that your activities were meaningful to you and has changed you for the better. Also, I believe you may have to record a video as a part your application?
5. The English requirement was something you and I have our doubts about. I had these doubts too and I can answer it for you. Well, there are multiple ways to assess and show UBC your level of English, such as through IELTS, TOEFL and etc. But I believe that A-Level or GCSE English Language (I believe English Literature may even meet the requirement) of a grade B or higher. I took CAIE IGCSE First Language English (they do not see Second Language English as the same and with that you must choose one of the following English tests) and received a B, the minimum grade to meet the English requirement.
As always, if you would like a true professional opinion and answer, don't hesitate to ask UBC admissions directly. They are very helpful and are willing to answer any of your questions.
I hoped you found this answer at least somewhat useful. All the best!