First off, congrats on being accepted to SJU. I thoroughly enjoyed my time there and it was a life-changing experience.
In regards to the first year work load, expect to commit probably about 2-3 hours outside of the classroom for every hour of class. This means that for the 11-12 credits you'll take each semester during the first year, you can expect anywhere from 20-24 to 30-36 hours work briefing cases and outlining. Now this isn't really an even distribution... at the beginning, it'll take longer to digest the information as you get used to reading cases, but as there will be less to outline, consolidate and review, your overall time will be shorter. As the semester goes along, the time demands tend to build. I generally felt that legal writing was a 2 credit class with 20 credits worth of work... that the memorandums of law and the legal research consumed far more time than the credit-hours would indicate. As a caveat, I wasn't always able to stay focused. I often had to find a private room with nothing to distract me to push myself through the material. If a person is able to stay consistently focused and on topic for longer stretches, perhaps they could cut down on the time.
During the first year I opened and closed the law school library both days each weekend. 10 am - 9 pm Sat, 12 pm to 11 pm Sun. This gave me about 22 hours of solid reading/briefing and research/writing. I also was able to catch about an hour worth of reading each day at work during lunch, and once or twice a week I would head up to the library after classes and close that at midnight. 22 weekend hours, 5 lunch hours and a couple miscellaneous hours before/after class usually gave me the time I needed to get it all done.
The only time I held aside for myself was Friday nights... the library closed early on Fridays (9 or 10, iirc), so my wife and I at least had 1 night a week together. Other than that, you can really expect to have no life for that first year. This includes Thanksgiving weekend...aside from few hours on Thanksgiving itself, because it was so close to the end of the semester I found that I had to lock myself away and take advantage of that time to work with my outlines.
Of the 60+ people in my evening class, I would say that only about 1/2 of them had a job at all, and of that 1/2, only half of those worked full time. At the end of the first year, almost half of my class switched into the full time day program. Of course, this was back before law schools had to report their PT numbers, so some people that couldn't get into the FT program would backdoor their way into a school by starting in their PT program.
For those of us that did work FT, I only knew of one person at a law firm... an engineer that was going on to be a patent law attorney. We had a bookkeeper, a couple salesmen, 2 nurses and myself... a blue collar telephone technician. Because my job is technically skilled, but basically brainless and repetitive, I found that I was able to stay sharp and focused during class and on the weekends doing my reading. If my job had required a high degree of 'brainwork', I'm not certain how I would have balanced it.
The workload I've discussed above is for the regular school year. During the final exam period (and generally the last couple days of classes before the finals period starts), I was always out of work and usually opening & closing the school daily. I also had failed to properly consolidate and outline during the semester, so as classes wound down I found myself looking at my unconsolidated class notes and briefs. Law school specifically tells you to start outlining early... and that's advice that I wished I had followed. On the flip side, the act of going through my notes, cutting out the excess and making my outline served as pretty good exam prep... to the point that sometimes, by the time I had my outline put together and finalized, I no longer needed it.
For reference, I was in the top half (top 40%?) of my class both semesters of the first year, with legal writing being the class that brought me down each semester. Without my legal writing grades, I probably would have been top 1/3. Four years later, at graduation I was in the top 30% of the entire graduating class... not law review or cum laude, but better than 70% of my peers.
So are you crazy for going PT while working FT? I was very envious of all the opportunities that FT students had that I had to pass on as a PT student. As time went on, I found ways to get part-time internships, get time off to accept a 10 week fellowship in DC, even participate in a clinic my last year where I represented my own clients in Family court 2x a week for the full year. The workload is manageable if you're committed enough and the opportunities are out there if you're creative enough. Only you know whether you can do it... for me, the question wasn't "Can I go to law school while working FT?", it was... "I have to work - do I want to be a telephone tech or do I want to be a telephone tech and a part-time law student?"
Again, congrats on being accepted. If you have any questions, plese don't hesitate to private msg me... I'm not active on this board any more.