disclaimer: I’m very new with both panda as well as python, so if this seems like a d’oh question i’m sorry 
as far as i understood from the manual panda works in a carthesian universe- which is theoretically infinite- and i’d like to know if i missunderstood or not and, also, what are these limits? aprox 32k or something along those lines?
You know, you can define panda units as whatever you want: centimeters or miles or light years.
A 3d universe can be as as long and wide as your computer can count. i wouldn’t care about that. Also I can’t imagine any application which needs an infinite space. Even if your world is huge, you can still split it up so that the player won’t notice anything.
Most people use 1 unit = 1 meter because well most persons are up to 2m in hight. By game is about spaceships so 1 unit = 1km, well because average cap ship is 1km in length.
Define your units to be what you will use your units for.
Note that there are real, practical limits in the floating-point world of computers. Although the single-precision floats used by Panda (and by your graphics hardware) can represent arbitrarily large values, they’ve only got about 5 or 6 digits or precision. That means as the numbers get larger, they get less precise.
It’s usually better to keep all of your numbers within a few thousand of zero. If you need to represent something farther away or bigger, move your coordinate system or change your units.
If you really want to represent a universe where human-scaled things appear to be in the same continuous space, you will need to apply some trickery.
David