Portals and rifts are two different things. Rifts are always rips with few exceptions, whilst portals are primarily doors, though some can be made from a rift. In addition rifts can lead between worlds and dimensions. Very rarely will they lead to other Universes. Portals on the other hand are quantum tunnels, and thus can lead to other Universes.
Which portals have you used? I helped design some of the portal stabilization structure framework for the ones I tend to use.
"Gimme a brief history of yours," said Maya. "I really think we have different ones." She took her omelet and set it down on the bar counter to munch on.
Ancient temple like atmosphere. Built to serve as a crossroads where various areas would intersect. Hallowed aura about it. Don't want to desecrate it-esque feeling you get?
Depends on how you see the world. Technology could be a way to explain magic. And the same could be said about magic, just a simpler way to do what technology does. Me personally, magic-based.
"Maybe you have the same one." She took a bite of her breakfast. "Did anything happen involving your soul?"