Is it possible to create weaker version of guncotton by replacing cotton wool with wood chips or linen cloth?
This article mentions hemicellulose from wood chips being hydrolyzed, not nitrated by a mixture of ethanol and nitric acid, while cellulose does get nitrated: Isolation of cellulose from poplar wood by nitric acid-ethanol treatment and its effect on the quality of films cast from ionic liquid

I also found a patent for Preparation of wood pulp cellulose for nitration which from the name alone suggests that cellulose from wood can be nitrated (the preparation described is purely physical, no chemicals applied).

Regarding linen and cotton fabric, they will work same as cotton wool. Cotton fabric is how nitrocellulose was first accidentally discovered (wikipedia article) and linen is made of cellulose fiber just like cotton (these fabrics have 94% and 95% cellulose respectively: flax, cotton).

Tldr:

Linen fabric, cotton fabric and cotton wool work equally well. It is possible to nitrate the cellulose in wood chips. Hemicellulose will (most likely) not get nitrated. No idea about smoke production and effectiveness so far though.