Tank Building and Edge Polishing

[plutoniumJoe]

Things are getting closer for my planned 180gallon. Just wondering is there any reason to have the edges that will be in silicone polished? All exposed edges will be polished but I wonder if it makes any differences for the non - exposed edges.

Also I plan on euro bracing, for a 72inch out of 1/2 glass would 3 or 4 inch euro brace be best? If it is euro braced should I also Cross brace at the 1/3 and 2/3 mark? I am trying to balance aesthetics with strength.