Bath Panel Plinths can be screwed to a main bath panel from behind to allow you to adjust the height of the panel or to make up for slanting bathroom floors.

How do you fill gap between bath panel and floor?

The best solution is a thin plastic trim. It comes in lengths or coils. Silicone 'might' hold It but a contact adhesive glue might be the best way to ensure it gets a good hold.

Should a bath panel touch the floor?

Like with Kitchen Units mate, the Bath like a Kitchen Unit, should be leveled to the floor high & low points in the floor. The full panel hieght at the low point on the floor and trimmed to the high point.