a gnome's shadow

[gnoams]

So my Pathfinder Society shadowdancer just got her 3rd level of the prc, so now her shadow comes alive. Huzzah. But as far as I can tell RAW (which I'm stuck with being a PFS character) the shadow I get is straight from the monster manual. The one in the monster manual is medium sized. So does my gnome cast a long shadow?
Is that intentional that all shadowdancers be they large, small, tiny, or colossal, all have the same size shadow?
Or did I miss something?

[gnoams]

A couple more shadow questions to add:
1) do I have to take the feats and skills listed in the bestiary or can I change them?
2) Shadows already get +2 channel resistance. Is the "+4 bonus to will saves made to halve the damage from channelled positive energy," in addition or instead of that?

[Drakkiel]

it's not your shadow coming alive...you summon A shadow...yes the one from the beastiary

1) RAW you get the shadow as is except for any exceptions listed in the class feature

2) they are both I typed so I think so...I'm sure the class feature gives them that so they are not insta-goo if your party healer channels