Thirtythree,
As an RA, I have an increased salary over the summer months (because I have more time to work in the lab). Most TAs don't get paid over the summer months. While that does mean they can take summers off, most grad students want to finish up school ASAP.
The sciences are usually very well funded by the NSF, a branch of the US military, and industrial grants. When you get outside of the sciences money can be hard to come by. This is an observations based on observations during my six years in graduate school. I do wish other programs were better funded, as I don't like seeing friends trapped in school for ridiculous amounts of time because they have to work part- or full-time jobs that are unrelated to their projects to earn the money needed to get by.
I don't know anyone specifically doing clinical psychology, but I would assume the worst.
Most everyone can make it through graduate school , but I would heed my advice "knowing the faculty in your department and having a good advisor is key to getting top funding dollars." Also Rumpltzer makes a good point about talking Ph.D. even if you're just looking for a masters.
In most programs, if you come into the school with good credentials and express interest in getting a Ph.D. potential advisors take note. Hour for hour, masters students usually accomplish much less than Ph.D. students, so the smarter advisors will often pass on students who aren't interested in an Ph.D. This is true even if they are smart, determined, and savvy. My advisor will not take masters students unless they are fully funded by academic fellowships.
Well, back to writing that journal article,
-Reader