I do modern astrology including modern sign rulerships-- and actually a lot of the old traditionalists used unequal house systems, as well. I think intercepted planets-in-signs have real meaning, but less for intercepted signs with no planets involved. Mercury is the planet ruling your 10th house cusp, and it generally suggests a career that uses your mind in some way, vs. physical work.
You do have intercepted planets in the sign of Capricorn: Uranus, Neptune, and the moon. The moon rules your feelings, and by its astronomical nature the moon is always changing; so this three-planet combo could give you very changeable moods.
Planets in intercepted signs can be boxed in, in some way. They can have plenty of creative talent (moon-Neptune) but difficulty in expressing it with a strong sense of "flow." So you may have a rich imaginative life, yet some barriers to expressing it in an outward, consistent way.
With respect to your major, it is best to think through in terms of the type of career you see yourself doing, say, 10 years from now; as well as the kind of home life you need to be happy. (No, this doesn't necessarily mean extreme wealth, as a Capricorn moon in the 4th might be happy without a lot of "stuff" and with the concept of down-downshifting.)
You don't indicate whether or not you are racking up student loans, but today this has to be part of many students' career determination. You can also nail down more completely what "job security" really means to you. There is a lot of information on-line about the jobs that pay well today. I haven't checked the top ten lately, but health-care is a growing field that is likely to be even more important, for example. A lot of students have artistic talent, yet most professional artists need a day-job to stay solvent. Even well-selling artists find that the arts market swings with the economy, so these are all things to keep in mind.
You also may suffer from crises of self-confidence, with Chiron conjunct your sun and Saturn opposite Mercury. So just realize that this can hit you from time to time, thank these feelings for "sharing" and go on to do what you say you are going to do.
If you really don't know why you are in school, it isn't a bad idea to request a leave-of-absence and to take some time off to work or travel while you sort out your future. College is just too expensive these days to spend it on a field that doesn't suit you; and then if you do discover your vocation, you may have to put in more than four years to complete it.
With Mercury, ruler of your 10th house cusp of career, in your 11th house, you would probably be happiest working for a large organization. In this "house of friends" you probably want to feel that your co-workers are a friendly bunch of people.
So what comes to my mind, anyway, is something to do with health care. This doesn't automatically mean hands-on patient care like nursing or physiotherapy, although Virgo rising can be good at this. You might look at health care administration, health insurance, or similar collateral fields. The 12th house rules hospitals, and you've got both Jupiter and Venus there, with Jupiter ruling your second house of money. Your sun conjunct Chiron can mean "it hurts to be you" but it can also confer huge amounts of compassion for other people less fortunate than yourself.
I wonder, also, with your strong Leo nature, if you would enjoy something in the hospitality (not hospital!) industry, like event plannning for a hotel or resort. This way you could be creative without having to be self-employed. With your strong 4th house nature, you might alternatively turn your artistic nature to commercial art and design.
I think once you visualize yourself in your ideal job 10-12 years from now, you can determine what sort of major will best send you on your way there.
