TarC only provide Diploma courses and Pre-U courses. If you want to get Diploma, TarC is a good choice but for degree, you only can get from university and not college. Or you can continue advance diploma in TarC then get a degree in UK. Another way is join degree course in other university after get your Diploma in college.

There is no way for you to go uni for degree with SPM level. You need a Pre-U level education such as Form 6 (STPM), A level, Matriculation, Australia Matriculation, foundation for the degree course or other Pre-U study. I do not know local uni offer foundation course or not but private uni are offering many kinds of foundations.

There are some differences between a Diploma and a Degree. Getting a degree is definitely better for your working next time. If your future boss want to promote someone to higher post, he will most probably promote the person with higher achievement and good working attitude as well.

There is no need to discuss against a "__ Science" course and a "___ Engineering" course. There surely will have some differences between the both. First is the course period, usually "science" course has shorter duration than "engineering" course because "science" course concern more on theory while "engineering" course will have a practical period (usually). This is one of the differences between 2 type of courses after some researches.

Since you are taking SPM this year, you should concentrate more on your SPM. SPM is not very tough if you willing to study. Add maths is not so hard too. Engineering course such as electrical engineering will have calculus which is differentiation and integration in Form 5 add maths. Without a strong add maths base, you will suffer in any engineering course. My friend studying in quantity survey also need to learn a lot of calculation. Same to electronic engineering, mechanical engineering and other science courses, there use a lot of mathematics which is harder than form 5 add maths.

Hope you can get well in your study...