The NirvanA page included two entries, one for the band NirvanA and one for the BuddhisT? concept of NirvanA. I created two new pages, one for each entry, and on the NirvanA page linked to both with a brief description of the contents of each page. Because there are countless cases where we will have this problem (AlabamA? is a state and a band, PaulSimon? is a singer and a Senator from IllinoiS?, et cetera ad infinitum) some solution will be necessary. WikiPedians can check out my solution and comment.
You were very right to do so. I am astonished that no one thought to do so before now. -- LarrySanger
A. I can't answer the question definitively but I can say that you can easily link to images elsewhere. So, perhaps as a temporary solution, you can always upload, elsewhere, an image, then link to it from WikiPedia. The wiki programmers must know more, though...
A2. The next release of the wiki software (usemod 0.92) will allow special characters to be used like ∞ for the infinity symbol, Δ for the Delta symbol (the triangle), etc. See the [list of standard characters] for more information. Most graphical browsers should implement these common symbols. For now, and for other symbols later, an image link to another site will be required. (I'm not sure if image uploading will make it into the next release, but it is a planned feature.) --CliffordAdams (working on the wiki code today)