This is a little thing, but I think the tiers of the achievements should be on more like a logarithmic scale, rather than a linear scale. For example, we have Goblin/Halfling/Dwarf, which require 50/100/150 Gentle Touch rewards. What if it were more like 15/50/200? This way the lower-tier achievements would be accessible to the more casual players, while the higher-tier achievements would require a comparatively hardcore amount of effort. Right now, the tier 3 awards don't require that much more effort than the tier 1s - if Fithz Hood can get Apprentice in a week, then he can clearly get Librarian in 2 weeks and Lore Keeper in 3 weeks.
On a related note, right now the award-based achievements are all scaled to the same amount (50/100/150), which seems unreasonable, since some of them are much harder to get than others. There's a reason Saboteur gives 1 gold and Survivor gives 9. No-one is ever going to get 150 Survivor awards without gaming the system. You would probably have to play on the order of 100,000 games to get it. Even getting 1 Survivor award is a big accomplishment in itself. I think the Survivor achievements should be something like 1/5/25 or something.