I loved XMP, and played it more passionately (for lack of a better word at the moment) for a very long time. It had the (near)perfect chemistry of complexity and style that I loved in games. I still do, but I can't find players. I basically would most prefer a direct port to UT2004 without fancy modifications. However, I can stand a few changes.
I realize that you have to be NEAR a deploy point you own. However on many XMP maps, there is usually one close enough that you can teleport back with plenty of time to spare. A gunner on offense would not be able to in time, but perhaps one that is doing free roaming will. However there are usually enough players on each team that the chances for teleportation advantages is pretty great. Basically, it will generally happen quite often in the larger servers. Also, it doesn't really take that long to choose a spawn point. I find myself doing it in less than a second. Less than half a second if I know the map. So quite honestly you can throw that factor away unless the player gets picky. Which will mostly only happen with the newer people.
Teleporting is basically the same as spawning when it is restricted by time. So why not just use suiciding? If teleporting has the same impact on score and energy etc. as suiciding, why implement it at all? With teleporting, the newer folks will use it more often, but XMP was about getting wise with experience and learning the tricks of the trade. If it was too newbie friendly, then anyone could know everything in short time! This would decrease the interest in for instance trying out new tricks. I remember when I first figured out how to get my boosters working so that I could jump higher, and then being excited as the possibility of actually navigating the Sunset Beach caverns properly arose. That was something that certainly made my XMP experience more engaging. When I think of XMP, I never thought of teleporting. That's when I think of ONS. It just seems too far off of the original, is what I'm saying.
On the idea of a spawning map: I guess it could work, as long as it stays relatively faithful to the gameplay of the original spawning system.
That's just my opinion, which I value sheerly because of the amount of time I spent on XMP and how much I loved every minute of it.