Another Little Suggestion for the New Ranked Queue

So I was in a ranked queue today, and I got first pick mid and the support was the last pick. I asked the support if he could last pick mid for me and I would first pick support for him and we would trade. He said yes. I first picked thresh for him, and everything was going fine. When the enemy picked Katarina mid, I wanted to counter-pick Diana. But the fifth pick said he wasn't sure if he had Diana mid. When his turn came, it turned out he didn't have Diana- so I was forced to play some other mid champion he had.

I was just wondering that we should be able to see our champion pool before selecting a champion so that stuff like these don't happen. And also not being able to choose chroma packs in the new queue. Please review this Riot before the real season starts.