Multiple Sessions in farm and RDP licensing

Hi,

I have been reading the technet guide on settings up a TS/RDS farm in server 2008, seems pretty straight forward, will be using round robin dns settings and session broker.

Question is, I am sure I read during the procedure you need to disable multiple sessions, im pretty new to all this stuff, so if this sounds silly, feel free to point it out.  How will this effect our practice?  We have doctors who run multiple exam rooms at same time, if they say for example are in exam room 1, log onto the RDS and do there stuff, but go to exam room 2 will they be able to log onto the RDS ? will the other session automatically disconnect from the other room?  I assuming this means :

Log into room 1..
Log into room 2, room 1 disconnects and users session follows user to room 2.

If someone with experience could clarify this, that would be great.

Secondly when deploying session broker on first RDS/P/TS (i dont know what to call it :( ), is it good practice to install licensing and gateway on the same server ? Do they have to be ?  (there are only going to be 2 servers in the farm)  im assuming licensing and gateway only have to be on the same server as broker ?  Is there much overhead with these extra snapin's, if so I can reduce the load accordingly to this server.

Oh one more as i think about it, RDS(TS) User cals are assigned to specific users in the GC or are they assigned when user logs on ? (are actual user base is alot different from our concurrent log on base)

Thanks for your answers