You have some good points - it is a problem when new player is overwhelmed by game features. We also should figure out a way to modify the deck editor for new players. If thy see 600+ cards they may want to give up the game right there.
I think the filtering mechanism might be made a little simpler and beautified a little. Here are some recommendations:
- Have two kinds of filtering mechanism: simple(default) and advanced.
- Simple filtering only searches cards by keyword and rarity (and maybe cost type)
- Advanced filtering are all the rest options.
- By default the simple filtering mechanism is shown and a button or link "Show advanced" would bring the advanced options.
- For keyword searching, instead of those techie select boxes use some kind of button-like image/icons along with text maybe (Horde, Alliance etc etc.) The keyword icons are already existent so use them maybe.
- By default only keywordless common cards should be shown instead of all common cards.