A few months ago I was unlucky enough to shatter my laptop's screen, so hopefully I can be of some insight now that I'm primarily using lab machines via an old laptop while I'm out.
James wrote:1. How many browsers do you currently have on your computer?
At home on my laptop, I have just two: Firefox and IE8. While out I run Damn Small Linux, which comes preloaded with Dillo and an old version of Firefox. Most commonly I connect to a machine in the CS department's general-purpose labs, which run both SeaMonkey and Firefox. However, I occasionally find myself on CE's workstations as well, on which my choices are Konqueror and Firefox (on Linux) or Firefox, IE8, and impressively, Netscape 7.1 (on Windows). The Windows machines in the other labs typically have just Firefox and IE8 available.
James wrote:2. What is your default browser?
At home, Firefox. While out, SeaMonkey where available, as I like to be able to check my mail as well.
James wrote:3. Do you change your default browser frequently or infrequently?
I've been a Firefox user for years, and at the moment have no plans to change that.
James wrote:4. Why do you keep several browsers on your computer?
I keep IE8 since it's part of Windows, though now that there's a 64-bit Flash Player out for Windows, I haven't had a reason to use it in quite awhile. There's one lab here on campus that goes as far as to have IE8, Firefox, Chrome, and Safari all installed, so I assume it's all to give people their choice of preferred browser. On the CS lab workstations, I can't really give a reason for the side-by-side installations of Firefox and SeaMonkey, as the department solely recommends the use of SeaMonkey and doesn't even advertise that Firefox is on the machines (it's only accessible by running it from the command line).
James wrote:5. Is there a downside to having too many browsers on one's computer?
Bloat and having bookmarks and such get out of sync are two possible reasons I can think of.
James wrote:6. Do you have a sense of "brand loyalty" or is your loyalty strictly to yourself? That is to say, if you believe browser X is now better than browser Y, do you change it to become your default in spite of the fact that browser Y has been your default for many months (perhaps even years)?
I used to be a die-hard Netscape fan, going as far as to use Netscape 4 on older machines that could have ran something like Dillo, but I stopped that around the time I made the switch over to Mozilla Suite. Now I'm primarily a Firefox user, but will basically use anything that gets the job done.
UserAgent: Mozilla/5.0 (X11; U; SunOS i86pc; en-US; rv:1.8.1.12) Gecko/20080303 SeaMonkey/1.1.8
Laptop: HP Compaq nx6325 - Turion 64 X2 @ 2GHz, 2GB DDR2, 100GB HD, ATI Radeon X300, 15" LCD, Seven Pro
Handheld: Palm Treo 650 - Intel PXA270 @ 312MHz, 10MB RAM, 32MB flash, 2.7" LCD, Palm OS 5.4