Teambuilder was good,
Not having to rush to paste your role in champ select to prevent getting stuck as support sounds fun.
But I read that the other aspect of teambuilder was to allow you to play troll picks if your team would want some crazy setups.... like adc/support mid.
As long as you go captain, it should be fine I guess.
I bought Nidalee with IP points. Having mostly played Ahri mid, I found it a lot harder to farm pre-6 and almost fell too far behind. But dat spear damage and cougar form doe...
That's just Nid. Once you hit your first power spike, you can wave clear quickly in Cougar. But you are relegated to a spear chunker. If you get a few spear hits, you can single handedly break a seige, win the team fight, etc.
With your speed boost in cougar, look to roam more often. It's so easy to assassinate people when your spear chunks ADC's for half their health.