Wow, some good ideas here, keep them coming. Many are impossible as suggested but could still be expanded upon.
'Gnomish oculus' sounds like an interesting idea. Although at the moment they can use cheap, mass-produced clockwork beetles to guard the perimeter, this can cause framerate issues if you make too many, so I might make them a little more expensive and come up with a different lookout method.
Gingerbread men.
Ehh... not really what I had in mind by nature magic. I was thinking more like... hmm, is there a way of spawning a whole bunch of friendly animals at the edge of the map? Calling upon Gaia's Vengeance would be cool. Turning animals sentient could also be thematically appropriate, although I don't think it would be especially useful. unless you wanted a bear as the mayor or something. Maybe spawning 'illusion' animals that couldn't do damage but would distract enemies...
Gnomes are currently [GOOD], although the idea of dark gnomes suggests that they can go either way. Is there any actual effect for making a civilized race [GOOD] or [EVIL]?
I've never heard the term 'gear punk', but yeah, that describes them a little better. Most of their current machines are clockwork based, with only a little bit of steam-powered stuff. The idea of making them not require fuel is certainly thematically interesting, although if so there will need to be some other method of limiting their production. Maybe once powered workshops come out they can get those as an alternate smelting/metalworking method. As for the vegetarian thing... well, I'll try it out and see if it makes the game better or worse.
As for castes, currently there are 21 basic castes for gnomes (each divided into male and female), one for each kind of craft ('craft' meaning a job where higher skill = higher quality items). They don't gain extra skill leveling for working in their craft, but they are born with an innate affinity for it, so children should work in them (with 20 year childhoods, it'll be good to have the kids be useful for something). There are also two special castes: an 'angry gnome' caste that has no innate skills, but is naturally prone to rage, has a very high anger level, and is alcoholic...good fighters, but also quite prone to going berserk, and a 'mad gnome' caste who has high creativity and learns skills quickly, but is usually the first to go stark raving mad when things start to go to pieces. Also clockborgs, but they shouldn't show up unless you make them.
I'll see about the manual. Speaking of which, how do you make the workshops look so good? Is there some utility that lets you design workshops in accordance with the raw format and lets you view them with the tileset?