Please let us view in-game chat.
Please give us a lobby for people spectating so we can comment between ourselves.
Give us the option to disable direct spectating. Sometimes I don't want to be watched, whether it's because I'm having a bad day or because I'm streaming. I understand people could still watch the other people playing with me, but it would at least reduce the amount of people that could watch.
Make the delay 5 minutes instead of 3. This reduces the ease of cheating for counterjungling buffs. This may not make a difference at high elo play, but at mid to low elo where warding enemy buffs/using common sense isn't common, it can make a LOT of difference.
Sometimes the auto-camera focus weird things, as mentioned many times already. I've just turned it off for that reason, but it's worth investigating.
Let us see names before having to hover over. I understand why you did this (read a red post about it), but I still feel like it's clunky and annoying.
Let us filter by champions if possible. For example, if I want to learn Lee Sin, let me search for Featured Games that have Lee Sin in them.
Include more elo ranges and let us select them. If I want to improve my 1400 play, let me watch 1400-1600 games. People don't make all the same mistakes in 1900-2000 that they do in 1400. :\
Let us have the option to only see games before a certain time point (5 minutes would be my ideal). Most of them are currently 10-15 minute range, and by that time you can already have missed 3-8 kills at least, and definitely have missed first blood.