Ok, wait.... who is this?

[Anonmon]

Indeed many things in the series left questions open, and so was the end not satisfying too in my point of view.
Takato smiled as he looked into the hideout, where Guilmon was. Why the hell did he do that? Did Guilmon return? Was there the door to the Digiworld open again?

Back to the topic, same goes to Alice. Indeed there is a lack of information about her. Who was she, and how did she act? Many questions which might be interesting to know aren't answered. That's the part I have to criticize (spelled?) at them too.

To answer your first question, YES a Digignome had created a new portal in Guilmon's old home.

[Thornwhistle]

Alice is the late granddaughter of Dolphin.

[Sylphstalker]

The Ghost references with regard to Alice are as JERI's ghost. Takato mistakes her for Jeri after she dissappears.
Alice is the Grandaughter of Dolphin Mcoy and i remember correctly she was still around after Dobermon snuffed it. I think that proves she's not just his creation.

[UnknownH]

The question was already answered.

[Blackjack Gabbiani]

Wasn't the thing about Alice being 'dead'...didn't that say "no longer being of this world" or something like that? Couldn't that mean that she exicted in the Digital World?

[UnknownH]

Yeah that's what he said.

[fred_18]

she looked pretty damn human and alive to me, not really sure if she died.

[Harie Krauzer]

Well see, that's the problem with ghosts. In some stories, they appear to be so alive that not even they know they are dead. I'm not saying it is the case here. I'm just saying there isn't really enough evidence by looks alone from what we do see.

[UnknownH]

The thing is, The guy who worked on tamers also worked on serial experiments lain and big O. Which have very confusing plot twists in it.
Plus It was translated from japenese so some errors are to be expected.