I've never seen a Panasonic plasma with taped foam blocks, so nothing to worry about there. As far the corner sticker goes, they are not included with every TV. Generally those are more common during early production run models, since that's around the time that retailers will be unboxing new models for store display. For example, my VT50 came with the sticker (purchased in May 2012) but my friend's GT50 did not (purchased in Nov 2012). Sounds like your TV was new to me.
ht Panasonic TC-P60ZT60, Monitor Audio: Silver RX6, RX Centre, Radius 90HD; Martinlogan Dynamo 700, Marantz SR5006, PS3, Oppo BDP-103D
2ch Marantz PM8004, Sony BDP-S1000ES, JVC T-X3 tuner, Monitor Audio Silver RX1, REL T3, Apple TV, Peachtree Audio DAC•iT
lr Panasonic 50ST60, Sony BDP-S5100