Most of what you’ve written is accurate as far as St. Andrews. My D19 is a current student. She’s reading psych and econ. Her classes generally have had a mid-term and final or 2 class tests, a lab report and final, or 2 papers and a final. The final is usually worth a minimum of 50% up to 70% of the grade. The students have a week in the middle of the semester together with up to 2 weeks at the end to catch up/study for their classes and finals.
While the amount of class time in the first year and second year is fairly equivalent to that in US schools, office hours and general professor availability is significantly less. Advising is also there but not as needed at the beginning to be honest because the curriculum is already set out for the first 2 years in most subjects. For example, psych takes psych 1 & 2, Econ takes intro to micro and macro. If you’re an advanced econ student you might take a combined micro/macro and a math for econ class.
Students are expected to read and learn quite a bit on their own and good study habits and discipline is important because students often have more free time than at US schools where students routinely take 4-6 classes a semester. Often there are required and recommended reading lists. Required will get you the basics but recommended fleshes out subject.
As far as university support systems….to my knowledge there’s nothing akin to a writing center, for example. Students are supportive of each other and I believe there’s peer to peer tutoring. My D didn’t utilize it if there is such an option.
It has been said before on CC that the UK system is closer to grad school than undergrad as far as academics and I think that’s true because of the focus on one or two subjects without much flexibility to change one’s area of study. On the social side, that’s where the grad school analogy ends: the students at St. Andrews are very involved and there are always many events occurring through out the year.