Had a chat with you earlier about moss, Im not too clued up on moss it but I really suggest you read the threads at the bottom of this post for some really good info.
But I've given your questions a go anyway!
1 & 2: How do i re pot it, what will it grow on? - I would scrape it or pull it from (I'm assuming) a rock. It should grow on rocks and wood aslong as it isnt fully suburged, to see how to get it to start growing a technique disscussed in a couple of the links is blending it with powdered butter milk to get it to grow on, well whatever you want really, unsure what the buttermilk would do to your tank tho, might be best to get it growing on your desired object somewhere else and transport it when it takes hold (I may be wrong, could be harmless).
3 & 4: How do i keep it alive? What are it's basic needs? - keep it moist and a little light, some people have suggested that moss grows better on a slanted surface(on that isnt level) its basic needs - Humidity and low light in my experience.
5: Will my salamander agree with it? - This is where I am unsure, this will probably vary greatly depending on the type of moss and your caudate. When collecting try to get a few different types incase you get something that wont work well, then you wont have waisted your trip. then I would try to identify it either on this site or with the help of google.
6: How fast does it grow? - Again I would say depends on the type of moss and the conditions in which it is kept.
7: Will it start to grow on glass? - It would grow on the glass, but I wouldnt worry about it taking over your tank.
8: hat conditions does it like? - See the answer to number 2
9: Could it kill my salamander? - See the answer to number 5
These links should be quite useful; as for aquatic moss, java moss is always a winner with caudates and easy to grow, or moss balls are great too!
These two are short but disscuss moss tips and compatibillity a little -
http://www.caudata.org/forum/showthread.php?t=58484
http://www.caudata.org/forum/showthread.php?t=58986
Johnny's post about his caudate bar that covers little on moss -
http://www.caudata.org/forum/showthread.php?p=196222
The mythbuster article talked about by Johnny in the previous post -
http://kwc.org/mythbusters/2005/05/mythbusters_breaking_glass_a_r.html
A British moss book might be of some help -
http://rbg-web2.rbge.org.uk/bbs/Resources/Fletcher.pdf
Hope this helps!
Cliff