1- Do as mention before by Michal.
2- Mentioned by lembas here and here
http://trisquel.info/en/forum/skip-login-window.
3- Midori uses about 8MB less than Abrowser. Remember that Trisquel-mini is
pretended to be for lightweighted use. You can install abrowser if you
prefer.
4- I would not be so anxious for another version. Trisquel is great as it is.
If you wanna change or add someting you are free to do it and ask for help
for it too.
5- I haven't tried a second screen.Out of ideas there. Make another thread
for that and you'll surely get more help there.