I was an RA in college, and in graduate school I was a residential hall director who hired and supervised RAs. I love res life so I am super biased, but here are my thoughts.
Pros, cons, considerations:
Yes, RAing is a time-intensive job. Generally we tell students that RAing is your second priority right after academics - and before anything else you may be involved in, including athletics.
Yes, RAs get days and nights off. How many depends on the college. But on-call work is not necessarily very time-intensive - you have to do rounds and respond to calls, but you may not get any calls and you may only get easy calls, particularly on weekdays. Also remember that on-call work is only one part of the job of an RA - there’s also planning events (we required our RAs to do one event per month; other schools have different requirements) and meeting your residents’ needs (some residents will have problems that are not call-worthy but will approach the RA about it). I also had a mandatory weekly meeting with my whole staff and biweekly one on one meetings with each RA.Otherwise we encouraged our RAs to be on the floor in their room most of the time in the evenings. Still, our RAs were very active in lots of other organizations on campus, so it’s possible to do other things - just not a lot of other very time-intensive things.
There is also, of course, training and move-in prep, which is its own beast but usually requires the RA to be back on campus about two weeks early. Training usually runs from early in the morning till late at night. It’s exhausting but a lot of fun. Another important consideration is that there are some holidays that we need RA coverage for, although usually local RAs volunteered for that.
Pros are meeting lots of people, having a stake in community building in college, having a great leadership position that looks great on resumes, creating a network that lasts for a long time (my RAs do amazing things and I know so many people through RAing, and my closest friends I met through my HD job - most of my friends are former res life). You also gain super crisis management skills - I have this weird thing now where I go into Zen Mode and start considering actions and options in a crisis because of my res life experience. Another pro of RA jobs is that it makes you eligible/more competitive for hall director jobs, which you can sometimes do in graduate school to save money. I lived in NYC for two years RENT FREE because I was a hall director, and I estimate that I saved at least $24,000.
Cons are the time involved, stressful on-call situations, sometimes there are perceptual issues with friends (not a huge problem, but a consideration - if your friends are hard partiers or like to smoke in their room…you can have issues) and being in a “fishbowl” - you have to hold yourself to a higher standard than your peers because you are always being watched. Also the standard ringtone on Verizon flip phones will always freak me out.
I don’t think that the hourly pay doing other work study positions would be more if you count the value of room and board. However, other work-study and general student jobs are certainly less stressful, and probably put more money directly into the student’s pocket. It’s a trade-off - the student has to decide what they’d rather do.
Advice
Yes, there are totally things your D can do as a high schooler that improves her chances. We looked at and took high school activities into consideration when we hired. Especially for our sophomore RAs, we looked for a track record of leadership, community building, and crisis management activities (to a reasonable extent). But we interpreted that broadly. Camp counseling was a VERY common entry point. We also had a lot of RAs who were prefects or the equivalent at their boarding school. Any kind of leadership in ECs in high school are also viewed favorably, as well as other organizations that involve community building and service. Lots of people did peer mediation/counseling/mentoring, too. Basically, we want to see that this person has a dedication to helping others and serving - and not that they’re applying because of the free room and board or some other reason.
Most of the other things @twoinanddone says are true, too. We definitely reviewed student history with infractions before hiring and any significant infraction is usually an automatic disqualifier, so obviously don’t violate policy.
Joining dorm activities as a freshman is a huge deal. If your D’s dorm has a residential hall council, she should run for it or get involved in it - we drew a lot of our RAs from that. (They plan activities and do a lot of other things that are great prep for RA work, and few people really want to get involved.) Getting to know current RAs is also an excellent way to increase chances. ALL our RAs conducted our interviewing process along with us at my institution. And while hall directors selected their own staff, we took recommendations from our RAs VERY seriously, and I heavily involved my RAs in the process of selecting new RAs - because they took their jobs seriously and would only want people on their team who wouldn’t drop the ball and increase their workload, but also because team dynamics in res life are SO important and I wanted RAs who would click with my current ones. Basically, if my RAs strongly recommended someone and there wasn’t another reason to think they would be a bad fit, I tried to hire them or at least encourage another HD to bring them onto their team. One really common thing was residents who were particularly helpful or involved in the dorms (aka residents who weren’t necessarily on dorm council but always had suggestions for the RAs about events, or helped set up or clean up after events, or always showed up for most events, etc.) were referred to me as potential candidates.
Basically though res life is awesome and I’d tell any college student who’s interested to try and pursue it!