Why am I not in level 2 now?

They were in part games bundles on sites like Humble Bundle, Groupees, Bundlestars, etc.

Once bundled, a game will remain on the bundle list, effected all future giveaways.

Read. the. FAQ. No really, the FAQ is just only about the very important things with no fillers(except examples).

Also, bookmark this will you: http://www.steamgifts.com/bundle-games

There's a lovely search engine on the left so you can check if a game you want to give away is or is not in the bundle list.

Welcome to SG.

discounted for approx. -95% or more on the steam store, price glitches, bundled in tier 1-2 in sites like humblebundle.

list: http://www.steamgifts.com/bundle-games

yeah they was, you can search for the list here:

http://www.steamgifts.com/bundle-games

Or they was on the middle and lower tier bundles, or very cheap on sales something like 95% ( for some regions ).
The FAQ explain it better:
http://www.steamgifts.com/about/faq