As somebody who's played ultiduo a lot and have considered making maps for it myself, I'll try and give you my two cents in on it.
First off, let's talk rules and logic. If I can recall correctly, the middle point opens up after about 5 to 10 seconds of the round starting. Each team's timer starts at 5 minutes, and it should take roughly 10 to 12 seconds for one person to capture the point. Respawn times (if I'm remembering correctly) is about 10 seconds for defenders and 4 for attackers. I'll need to check my memory on the logic, but that sounds about right.
If you need anymore information, let me know: I'll try and help in anyways that I can.