The first harboured heartbreak: there simply would not be enough time or space to include all the interesting, urgent work jostling to be seen and heard. The second was altogether more heartening: all kinds of artists were declaring they had something they wanted to say in response to a suggested theme of "identity" - and for them, the free-ranging context of Arches Live acted like a welcome mat for risk-takers and provocateurs.
If tough choices were the order of many working days - not just for the programming team, but for the technical crew juggling the wishlists of selected performers - the outcome is a five-day event (spread over two weeks) that is truly hard to niche beyond a collective desire to communicate with audiences.
Whether that is in terms of a profoundly held political viewpoint, a personal experience or an open statement of unresolved questions - with the issue of identity lurking somewhere in the background - the result is a reminder of how our own perspectives can shift, be jolted into new understandings, by an image or a phrase that changes the ordinary into something extraordinary.
Arches artist-in-residence, Adrian Howells, knows from his own series of one-to-one performances just how seemingly simple actions - the washing of someone's feet or a hug - can often unlock emotional responses the participants themselves did not anticipate. So when Howells freely admits the first time he saw Ian Johnston dancing, he was overcome by tears, it is obvious there is more to He's The Greatest Dancer - the show they're presenting with Gary Gardiner - than a cocky title.
That first encounter took place during Howells's recent residency with Sense Scotland. At the end of an evening of mostly musical performances, Johnston arrived on-stage and as soon as Kylie's All The Lovers kicked in, he went into his dance. "Dancing for the pure joy of it," is one of the ways Howells describes it. Johnstone, sitting beside him, grins impishly as Howells gets a bit moist of eye again.
A degree of unspecified learning difficulties has left Johnston shy of saying much, especially to people he doesn't know. But when the talk turns to favourite tracks - not just numbers by Kylie, but Beyonce and Lady Gaga - he lights up, and whispers to Howells about loving to dance. Afterwards, Howells will muse on how "we all assume meaningful communication has to be through words. But words aren't how Ian expresses himself. Instead, he communicates with his body. He puts what he feels into his dancing. He's totally unselfconscious, totally in the moment when he's dancing - there's no pretence. It's authentic in ways most performers can't be anymore. I actually find it humbling because of its purity. And I hope that's what an audience sees on-stage. I hope they see that 'difference' can be something special."
When Arches Live gets under way tomorrow night, Steve Slater will find himself performing in front of an audience for the first time in decades - well, barring a brief foray on stage last year at Tate Britain. Between Atoms And The Stars, with the subtitle Or How To Describe Art To A Dead Astronaut marks Slater's re-entry into the world he once inhabited, before he turned his creative energies into programming, at Glasgow's Tramway, and thereafter into co-producing other people's projects. He is currently carrying the Dance Portfolio at Creative Scotland, among other things.
"None of this was really on the horizon when I approached the Arches," he says, "so now I'm doing this show with very little time - but maybe that's not such a bad thing."
He does laugh as he says this, because in fact he's relishing reconnecting with the ideas, the skills, the challenges that absorbed him as an arts student.
"Will any of it still work? I'm actually really keen to find out," he says. "To be in the Arches, doing a performance is a bit like going into freefall. But I think my own performance background was always a part of my vocabulary in the conversations I had with the artists I commissioned or programmed.
"We'd talk in the same way about their projects - I'd start suggesting things, and probably they wished I wouldn't. Now Arches Live has freed me up to do it myself. It's made me look again at why this kind of work has always mattered to me. Not just going back to the days when, because I didn't have a car, any equipment had to be carried on trains and buses, but to what I do now.
"Really, it's to do with that special kind of magic where - audience or performer - you're no longer in the room. You've been transported, in your head, to some new dimension. Will that happen at the Arches? I've no idea. But I just feel really engaged with it at every level, and willing to test things out for myself."
Land's End, the new show from Thomas Hobbins, was a test that started with the notion of him cycling with a friend from Land's End to John o'Groats. In time, that journey became the stuff of funny stories Hobbins would tell down the pub.
Now it has become a test of another kind, one that involves Hobbins stepping out from behind the comic book/super-hero personnas he's deployed provocatively in his earlier solo shows.
He is frank about the process being more gruelling than he had expected. "I think I've been putting off making this piece for ages," he says. "Because, yes, it does feel very exposing. I've been making jokes about what went wrong on that journey as a way of distancing myself from it. Maybe I got bored of doing that. Maybe I just wanted to see if I could push myself to make this piece and then move on.
"I've always liked the challenge of the unknown."
Arches Live'13 begins tomorrow night and runs to Saturday, September 28.