Just a few suggestions.

I would probably not give straight weapon proficiencies to any of the woodland races as in the novels ive read most woodlanders had very specific weapons they liked to use. Maybe something like weapon focus with their racial weapons but extra penalties for using non proficient weapons.

Anyway heres some suggestions for racial weapons

Mice - Quarterstaff, Sling, Short Bow

Squirrels - Longbow, Javelin

Otters - Javelin, Sling, Shortspear

Hares - Composite Longbow(based off the Longbows used by Colonel Clary and Friends in Mariel Of Redwall), Longspear, Shortspear, Quarterstaff, Short Sword, Long Sword, Sling, Dagger(They do recieve a lot of military training and constantly practice so i thought it was fair to give them a bit more)l

Moles - Claw, Club, Warhammer, Flail (Based on the Mallet and Flail wielders in the novel with Urgan Nagru the Fox Wolf), Sling

Shrew - Rapier, Sling, Dagger

Hedgehog - Club, Sling, Great club (Havent really seen them use any other weapons)

Badgers - All Simple and Martial weapons (they are supposed to be great warriors after all)

Vermin characters should probably get more general proficiencies as in the novels they're generally armed with a wide variety of weapon types. The other way you could do it would be to say they were proficient with whatever weapons they start out with.

Stat wise the badger does seem underpowered compared to how they appear in the novels. I agree with Jathki on this point , badgers should be incredibly powerful compared to anyone else as several times throughout the series its pretty much them on their own or with a small group of allies versus a vermin horde and they either win or inflict massive casualties before dying.

The only other thing i can think of at the moment is that maybe hedgehogs should have a natural armour bonus anyway, maybe +1 or +2, and curling up increases it rather than granting it.

Other than that it looks great, good luck with getting it off the ground.