PoseDrawSki sez: Not Spaggetti, it be Rossini they be lining up to hear in this opera palace.
I'm not sure what you mean by the lines? There are natural lines because the cast shadows on the steps create them, and all throughout. It's very VERY linear, this one. So putting in lines is in keeping with the image you're replicating.
As to the statue's head, you should make one up or better, look at another pic for reference. Ye dassn't leave 'er headless. Would be a threat to the haberdashers union and ye don't want t' spike their ire unless you want to be pin-cushioned by hat pins. Nay lad. Give 'er a head.
As to the filligree on the column ends, just make up something that would be seen in the columns' capitals. Usually some kind of scroll design. The only real problem would be to not pick something consistent.
Yer doon great, lad! Might want to look for an OBE in yer Christmas stocking this year.
ˇVaya con grandiose pick up lines for the lassies of breeding! (Spaghetti may not be the bait they're hitting on today)