You should never think your voice isn't important. As long as you voice it a respectful, thoughtful way, then it matters just as much as Steve's, Brian's, or anybody's. You completely were respectful, but I think that is obvious. :)
I'll give a few of my thoughts. I'm no expert on the format, ive been in it for a little over a year and I get to play about once a month (maybe twice) at local tournaments in Michigan. That doesn't mean my opinion doesn't matter, the exact opposite, but I wanted to give insight on what I see and how I see it.
I've been in the camp of restricting Gush for a while, but I'm not so sure anymore. The card is obviously powerful, no doubt there. I think people's problem, lies more in the archetype and maybe they get too focused on a single card. Low land count, lots of cheap (or free) cantrips, with the best finisher in vintage (in my opinion) - Mentor. This creates a see saw with Shops decks, as Shops prey on Mentor decks, because of deck design that Mentor loves.
There's nothing wrong with that in essence. I think each deck should have a natural predator in vintage. That creates balance when no deck has a gleaming weakness. the question I would have with Mentor is that Shops is a natural predator, that's only one archetype, so is there enough balance with other decks or is it too unfair against all other decks?
Mentor. I understand and agree with a lot of what people say, but I'm not a fan of restricting win conditions. However, this creature goes both wide and big, unlike any other creature in the format. That's not necessarily a good thing in vintage. The card in a vacuum, not the deck, has no really good predator.
On phrexian spells
I hate Mental Misstep as a card. Its my least favorite card in vintage. It's not fun to play against and is not fun to use. However, that in itself is not a valid reason for a restriction. Though, for argument, if you restrict this card and only this card, I think Mentor gets better and that's a scary thought. Say for example you replace this with 3-4 copies of Spell Pierce. You removed a glaring weakness to Shops and made it stronger against its natural predator. I'd worry about this restriction.
Gitaxian Probe is the more problematic card of the free spells. It gives perfect information, it's free, it replaces itself, etc. it removes the critical thinking part of magic when I know what someone has in their hand. You know what exactly to play around. Especially if you're a combo deck, this is incredibably important information. It results in a lot more turn one kills. Not to mention this is excellent for Mentor.
However, I question what a restriction for Gitaxian Probe would do to PO decks. Would that make PO unplayable? I'm not saying that's the case, but I think the decks may need to be redesigned a bit. It would certainly weaken them and they aren't in the best place in vintage right now as it is.
If I would had to make a decision at this moment, I say no restriction. I do enjoy the format as it is, as I have an absolute blast playing the format every time I do. However, that's possibly maybe because I don't play as often as others and maybe because I'm not afraid to play tier 2 or 3 decks. I'm planning to play Merfolk soon and I want to try or delver one day. I play for my own reasons and in my own way. Fishy!!!!
If they were going to restrict a card, I'd like to start with Gitaxian Probe and/or Misstep. That's just my two cents.
*edited note: forgive any grammatical errors. I typed this fully on my phone.