There is no indication that she summoned him or turned him into anything. He woke up in Silent Hill, and she found him. She led him around town looking for the Flauros, yes, but that's the only specific indication of any kind of plan. We can suppose further involvement, but we do not know for a fact.
...are you kidding me? It's specifically said, with IN-GAME DIALOGUE, that Alessa made Travis into her conduit, and since she controls the Otherworld Travis is travelling through, and since she can warp him around at will, and since it's explicitly revealed that she's the one digging up Travis's past, it's very obvious she summoned him.
Quit being stubborn.
There is no indication that this was a conscious decision rather than reflex action, although the distinction may be irrelevant in this case.
Good point, but since the Flauros amplified thought, she had to atleast have been THINKING of soul-splitting.
While her mind definitely shapes her reality in Silent Hill, there's no indication that she consciously traps her enemies; it could be that they were trapped by the nature of the world itself, which had gone out of control.
The cosmology shown to us in the series makes it fairly clear that by default, people are drawn into their own Otherworlds. If you wind up in someone else's (instead of merely bleeding over with someone else's, like in SH2), it is a deliberate action, as shown in SH3 and SH4 already. Why should Alessa, a psychic who's demonstrated conscious control of the Otherworld, be any different?
While we can assume she was doing something with the Seal, we don't know for a fact her specific intentions. All the Book of Lost Memories states on the subject is she attempts to escape from Dahlia and destroy herself. I believe the Seal of Metatron was supposed to primarily be protective, but had multiple undefined uses.
It's been factually elaborated that Alessa was using the Seal to destroy her self and take God, and her Otherworld, with her. The rare time Dahlia wasn't COMPLETELY bullshitting, I suppose.
We know the Memory of Alessa tries to kill Heather for this reason, but even if she were the one who characterised the darkness in SH3 (which I don't necessarily believe it was, and the BoLM only hints at that idea as far as I can see) that still doesn't mean she controls every element of it.
Well duh. I'm only saying she controls the non-human monsters, though, which is true. Stop taking things a step further than I'm trying to in order to counterpoint, it's a strawman.