What would the speed of a Sverfneblin character be?
There is no speed entry in the advanced race guide and the prd also has no speed listed for these creatures.
I suppose it would be 20feet/round, just like another gnome.
On the other hand 30feet might as just as wel be possible.
The entry to the racial traits says that "Svirfneblin are fast and observant..."
And also 30ft is 'normal speed'. You might reason that since their is no explicit speed entry, that the Svirfneblin has a normal speed.
The craft skills are most usefull when there is plenty of downtime for the players.
but still keep in mind: while all the other player are having a great time, patying and drinking,during the downtime phase, the hardworking crafter gets the prime magic itzms at half price!!