tell application "iTunes" 
{artist, duration, rating, album, genre, name, id, year, persistent 
ID, database ID} of current track 
end tell

It shouldn't take longer than the fraction of a second.

And then

tell application "iTunes" 
data of artworks of current track 
end tell

which shouldn't take longer than 5 seconds (mainly because Script 
Editor needs to display binary data as hex values). 
...