I can't say anything useful about fonts (other than that a friend of mine will hunt you down and hurt you if you use Comic Sans).
Two versions of LyX sharing the same version of MiKTeX is no problem. Having two versions of MiKTeX coexist is slightly tricky. Bear in mind that when any program (including LyX) calls any TeX executable, such as pdflatex, you will typically run the first matching program found in the command path. So if MiKTeX 2.9 precedes MiKTeX 2.8, calling "pdflatex" without a full path specification will always run the 2.9 version. I *think* you can circumvent this by specifying the path to whichever version of MiKTeX is not default in the configuration of the version of LyX that needs it (in Tools > Preferences > Paths > PATH prefix. A simpler (?), cleaner (?) solution might be to create a new user account on the machine. Let's say your normal login is configured with the older versions of MiKTeX and LyX. Install the newer versions using the alternate login, and specify that you are installing them just for that user and not for all users. Then you just have to switch to the right account for whichever version you want. Paul
