It's too late at night for a full post, but I can hit a few points.
Did you see the effect of how 1 participant could change the flow of events?
Actually, I thought I made a merciful choice here. I saw two ways I could approach your invitation for others to participate:
1) Additional participants, if they assist, assist under their own power - that is, they use skills of their own to boost your chance of success. Thus, you don't need them, but they could help if they succeed at their own skills checks. (Bonus Skill Checks is M1@4 - very simple magic, in bias terms.)
2) Additional participants are expected, and the magic is more difficult to perform without them. They don't need to make skill checks to assist because their participation at your behest is part of your ritual, but you are relying on them joining in and so suffer a penalty if fewer than expected participate.
Given that I thought it highly unlikely that any creature in range of your broadcast thought projection even had the ability to speak (or project thought), I thought it at least as unlikely that you would garner even a single participant. It would require a general effects roll to determine if anyone or anything on the other side of the portal was both (a) a valid potential participant and (b) decided to participate. Given my view of the situation, it would take a strongly positive roll to mean you got your participants, and making that roll, of course, would open you up to the possibility of negative results.
Even with that in mind, the sit-mod would likely be something like -5, +2 per additional participant, or -10, +3 per additional participant, or something along those lines. A threshold would need to be reached before the bonus for the assistance began to outweigh the penalty for not actually needing the assistance.
So as I said, I thought it more generous to assume (1). Perhaps I ought to have rolled a GE for if anything on the other side of the portal heard you, wanted to help, and was willing to invent a M1@4 Bonus Magic Skill Check spell based on joining in with another caster's chant. Perhaps I ought to have, or perhaps I know something you don't.
I admit that I never considered whether your parents would join in or not. That is because I knew they were not in the immediate area, I understood you to be projecting thought to the immediate area only, and I didn't think you were also uttering the incantation across your private telepathic links with your parents. I was under the impression they never even knew you were casting.
What kind of range were you expecting on your broadcast thought projection? Perhaps we ought to have explored that in more depth. I wasn't thinking anything more than a 30 meter radius.
Ritual factor = 5+10+15+3-25 = 8
Yeah, I added in the +10 for spirit form after the fact and neglected to update the math to reflect it. However:
I just wanted to tell you that the ritual is actually a unison prayer which could be considered alliance magic considering the act of healing wound and I have "1@5 Religion, undisclosed alliance faith M1@0".
Perhaps I should have asked whether this were holy or arcane, but I saw nothing in this spell to indicate that you were praying to God to close the rift for you. I'm not saying all holy magic has to include a direct appeal to a deity, but ultimately the distinction is this: with arcane magic, you manipulate the magic yourself. With holy magic, you petition some other entity to manipulate it on your behalf. Under that definition, do you still think was alliance holy magic you were attempting?
(Also, if you try to do holy magic without disclosing the religion, you will irritate me. I'm not saying I won't let you, necessarily - hasn't happened, so I don't have to decide yet - but it would bother me. It's hard for me to run the game if I don't know what going on.)
I will then concentrate for 8 minutes then try to stop material space/time.
I'm about to fall unconscious, but I thought I'd warn you that I'll want to know more about this. I'm not even 100% sure it's psionic, much less willing to hazard a guess as to minor details like area of effect, "duration," whether you intend to affect both sides of the rift or just one, etc. ...