The desire to spit is not uncommon. This may indicate that your father perceives he has a lot of drool or saliva in his mouth, and wants to get it out. Drooling is very common in LBD and other atypical parkinsonism disorders. It can indicate dysphagia (swallowing difficulty). Has your father had a modified barium swallow study performed recently?
There is treatment for drooling but other than botox everything is anticholinergic and should be avoided.
A stooped walk is a symptom of "parkinsonism," and is common in LBD (for those with parkinsonism).
I've not heard of anyone wanting to sit on the floor but this doesn't particularly surprise me.
Have you looked over the LBD symptoms listed on the LBDA website? This link may work:
http://www.lbda.org/category/3438&cfid= ... mptoms.htm