Maybe Potlatch2 has not icons for all kinds of PIs and map features.

When you want to add a node or Building with http://wiki.openstreetmap.org/wiki/Tag:shop%3Dchemist then add only the node by hand and give it a key-value combination by hand. Maybe you have to switch to advanced mode in Potlatch2.

Alternatively you can open a ticket or feature request at trac.openstreetmap.org in order to add an icon to P2.

Or try one of the other editors … see http://wiki.openstreetmap.org/wiki/Editing